Preparation for online demo.

Split general playback code into tests/playback.js.

Use timestamps from recording with proxy to playback in realtime.

It's less efficient on average that base64 (150% vs 133%). It's
non-standard (0 shifted to 256 before encoding). And I rarely use it.

Generally, most servers send hextile updates as single updates
containing many rects. Some servers send hextile updates as many small
framebuffer updates with a few rects each (such as QEMU). This latter
cases revealed that shifting off the beginning of the receive queue
(which happens after each hextile FBU) performs poorly.

This change switches to using an indexed receive queue (instead of
actually shifting off the array). When the receive queue has grown to
a certain size, then it is compacted all at once.

The code is not as clean, but this change results in more than 2X
speedup under Chrome for the pessimal case and 10-20% in firefox.

- This allows the recorded data to be immediately usable by
  tests/vnc_playback.html

Turns out when Windows is running in QEMU and a window scroll happens,
there are lots of little hextile rects sent. This is slow in noVNC.

- Some recording/playback improvement.
- Add test harness to drive playback of recordings.
- By pulling off the rect header in one chunk we get a 3X speedup in
  Chrome and a 20% speedup in firefox (specifically for the scroll
  test).
- Also, get rid of some noise from creating timers for handle_message.
  Check to make sure there isn't already a pending timer first.

New API:

To use the RFB object, you now must instantiate it (this allows more
than one instance of it on the same page).

    rfb = new RFB(settings);

The 'settings' variable is a namespace that contains initial default
settings. These can also be set and read using 'rfb.set_FOO()' and
'rfb.get_FOO()' where FOO is the setting name. The current settings
are (and defaults) are:
    - target: the DOM Canvas element to use ('VNC_canvas').
    - encrypt: whether to encrypt the connection (false)
    - true_color: true_color or palette (true)
    - b64encode: base64 encode the WebSockets data (true)
    - local_cursor: use local cursor rendering (true if supported)
    - connectTimeout: milliseconds to wait for connect (2000)
    - updateState: callback when RFB state changes (none)
    - clipboardReceive: callback when clipboard data received (none)

The parameters to the updateState callback have also changed. The
function spec is now updateState(rfb, state, oldstate, msg):
    - rfb: the RFB object that this state change is for.
    - state: the new state
    - oldstate: the previous state
    - msg: a message associate with the state (not always set).

The clipboardReceive spec is clipboardReceive(rfb, text):
    - rfb: the RFB object that this text is from.
    - text: the clipboard text received.

Changes:

- The RFB and Canvas namespaces are now more proper objects. Private
  implementation is no longer exposed and the public API has been made
  explicit. Also, instantiation allows more than one VNC connection
  on the same page (to complete this, DefaultControls will also need
  this same refactoring).

- Added 'none' logging level.

- Removed automatic stylesheet selection workaround in util.js and
  move it to defaultcontrols so that it doesn't interfere with
  intergration.

- Also, some major JSLinting.

- Fix input, canvas, and cursor tests to work with new model.

The following API changes may affect integrators:

    - Settings have been moved out of the RFB.connect() call. Each
      setting now has it's own setter function: setEncrypt, setBase64,
      setTrueColor, setCursor.

    - Encrypt and cursor settings now default to on.

    - CSS changes:
        - VNC_status_bar for input buttons switched to a element class.

        - VNC_buttons split into VNC_buttons_right and
          VNC_buttons_left

        - New id styles for VNC_settings_menu and VNC_setting

Note: the encrypt, true_color and cursor, logging setting can all be
  set on load using query string variables (in addition to host, port
  and password).

Client cursor (cursor pseudo-encoding) support has been polished and
activated.

The RFB settings are now presented as radio button list items in
a drop-down "Settings" menu when using the default controls.

Also, in the settings menu is the ability to select between alternate
style-sheets.

Cookie and stylesheet selection support added to util.js.

Interestingly it turns out that using the native base64 routines does
not improve performance. Likely because the actual time is in
marshalling/unmarshalling between strings and arrays (and associated
garbage collection overhead) which has to be done either way.

mootools is no longer needed. The bug that the FABridge test was
testing has been resolved in web-socket-js so it's no longer needed.

Looks like disabling web-socket-js debug messages by default that we
get a minor speedup.

Python proxy should support both 75 and 76 (00) modes. Also, update ws
test to more reliably hit the WebSockets ordering/drop issue.

Now working under Arora 0.5.

But not Konqueror 4.2.2 (WebSockets never connects).

IE support with excanvas still pending.

Refactor how settings are passed around.

On path towards removing dependency on mootools in non-UI code.

Also add a wsencoding test client/server program to test send a set of
values between client and server and vice-versa to test encodings.

Not turned on by default.

Add support for encode/decode of UTF-8 in the proxy. This leverages
the browser for decoding the WebSocket stream directly instead of
doing base64 decode in the browser itself.

Unfortunately, in Chrome this has negligible impact (round-trip time
is increased slightly likely due to extra python processing).

In firefox, due to the use of the flash WebSocket emulator the
performance is even worse. This is because it's really annoying to get
the flash WebSocket emulator to properly decode a UTF-8 bytestream.
The problem is that the readUTFBytes and readMultiByte methods of an
ActionScript ByteArray don't treat 0x00 correctly. They return
a string that ends at the first 0x00, but the index into the ByteArray
has been advanced by however much you requested.

This is very silly for two reasons: ActionScript (and Javascript)
strings can contain 0x00 (they are not null terminated) and second,
UTF-8 can legitimately contain 0x00 values. Since UTF-8 is not
constant width there isn't a great way to determine if those methods
in fact did encounter a 0x00 or they just read the number of bytes
requested.

Doing manual decoding using readUTFByte one character at a time slows
things down quite a bit. And to top it all off, those methods don't
support the alternate UTF-8 encoding for 0x00 ("\xc0\x80"). They also
just treat that encoding as the end of string too.

So to get around this, for now I'm encoding zero as 256 ("\xc4\x80")
and then doing mod 256 in Javascript. Still doesn't result in much
benefit in firefox.

But, it's an interesting approach that could use some more exploration
so I'm leaving in the code in both places.

- By dereferencing the 'data' field of the imageData object before the
  loop, the hextile performance on Chrome is down to 140ms or so for
  a full 800x600 update. Still have to fall back to Canvas operations
  for firefox.

- Fix RQ empty after reorder bug.