Closes #434

The current noVNC release is 0.5.1, but package.json still
says version 0.5.0.  This fixes that.

Fixes #441

Support ExtendedDesktopSize and SetDesktopSize

* Added new tests for the setDesktopSize encoding
* Added new tests for the ExtendedDesktopSize encoding

* Added a resize request (setDesktopSize) triggered when connecting and by
  changes to the browser window's size.
* Hid the view-drag-hand when the display area is the same or smaller than the
  remote session size.
* Added a setting for the automatic resize feature.
* Updated vnc.html and vnc_auto.html to reflect the changes to the UI.

keysym.js needs inclusion in debian's install list

* Support sending the setDesktopSize encoding (client -> server)
* Support recieving the ExtendedDesktopSize encoding (server <- client)

* Split viewportChange into two functions, one for changing size and the other for changing position.
* Modified viewport code to be capable of changing to a bigger size in the context of a
  client-initiated resize.
* Made clearer distinctions between when viewport-clipping or not.
* Added public function for telling when viewport-clipping.
* Updated tests that were using viewportChange.

Unregister event listeners from websock.

Prevents possible memory and event notification leaks when tearing down
connection and reestablishing a new one.

Loads keysym.js

Without it, `XK_ISO_Level3_Shift` (at least) is undefined.

Bonus 3 bug fixes:
 * Meta is 0xFFE7 not 0xFE07
 * Super_L is 0xFFEB not 0xFFEC
 * Super_R is 0xFFEC not 0xFFED

The HEXTILE test which tested for a background tile followed
by an empty tile was only wide enough to actually test for one
tile, thus not actually testing the functionality.  It now actually
uses two tiles, thus actually testing the functionality.

Fix for typo from a recent pull

There is a minor typo in the recent pull  Simple fix.

Closes #412

Previously, if a HEXTILE tiles was received with a subencoding
of 0x00, it would draw a rectangle using data from the render
queue, which would result in random colored blocks when using
the HEXTILE encoding.  This is the result of a miscopy during
the refactoring.  It now has the correct functionality according
to the RFB protocol specification, which is to draw a rectangle
with the last set background color.

Closes #411

Previously, we were using the karma-sinon-chai package to
provide sinon-chai to karma.  This used an older version of
sinon-chai, and looks to be no longer maintained (it's been
a month since sinon-chai was updated).  A new package,
karma-sinon-chai-latest, is now used.  This package uses the
latest version of sinon-chai and sinon, just like karma-chai
uses the latest version of chai.

Commit 795fca23 changed the default
size from 640 to 240.  This broke a couple tests which depended on
the default size being 640.  Those tests have now been fixed.

Added in guidelines for contributing to noVNC

In CONTRIBUTING.md, you can now find a set of guidelines for
contributing to the noVNC project.  They detail coding style
information, requirements for pull requests, and how to run
the unit tests.

This fixes an issue where, when using true color, the changeCursor
function would not actually write the cursor to the target array.

Fixes #407

Fix subprotocols

Broken by b1dee947

The latest version of Node.js has a bug that
affects the Karma test runner.  A patch has been
merged to Karma, but has not landed in a version
yet.  Until a new version of Karma is released,
we should keep node at 0.11.13.

See karma-runner/karma#1182

(cherry picked from commit 9af2346a0cead634f3af5f390770ea65929c1f4a)

Make Utils.js use Object.define to modify Array

Previously, we were modifying Array's prototype using
simple assignment.  This can mess with enumeration/iteration.
Thus, we now use Object.defineProperty with enumerable set to
false.

See #366

The readme was using the URL for the 'refactor/cleanup'
branch, which doesn't exist anymore.  It now uses
the badge for the master branch as it should.

This patch adds support for using relative paths
with the '-r' or '--relative' methods.  This can
be useful if you want to output HTML (with the
'--output-html' option) and use it in a webpage.

Additionally, the '-o' was removed from the documentation
of '--output-html', since it hasn't worked for that in a
while ('-o' means open in browser instead).

There was a race condition in Display#clear on IE10
because we resize and then clear that causes the canvas
to not actually end up cleared.  Clearing the current
viewport first solves the issue.  It doesn't appear to
affect other platforms, so it's inside a engine check
(`Util.Engine.trident === 6`).  Once we stop supporting
IE10, we should just remove this, because it's not the best
to have Engine-specific code.

Because we use the XOR (`^`) operator, the button mask must be
set before a MouseUp event happens, otherwise we'll send a pointer
event like it was a MouseDown event.  The button mask was not set
in one of the tests, so the test was failing.