Check whether printer is online when calling send()

Add optional wait timeout in milliseconds to printcore send, send_now

Fixed python-n00b error

make send_now check that the printer is online before talking to it

webinterface.py compatibility with Python 2.6 

Added web interface

PHP parser

Added a little parser for the XML status returned by pronterface.

xml format fixed

Fixed background colors when using dark themes

Projectlayer processing a zip of bmp files

The projectlayer file dialog now accepts files with the extension
*.3dlp.zip and will extract the contents to a temporary folder. It then
finds any *.bmp files and adds them as a set of layers.

Notes:
- Offset works, but currently scale does not affect the bmp files.
- *.3dlp.zip was chosen to mark the file as being for dlp based
resin printers, but also processable by regular archive programs.
- Have also introduced a checkbox to let the user decide to display
  fullscreen or not, as they may want the window dragged to a second
  output.

DO not clear sent lines dict after each ok - fix for firmware sending resend after ok triggering keyerror