attempting fix for issue 305

Encountered https://github.com/kliment/Printrun/issues/305#issuecomment-12306186
This edit removed the error, but I don't know what the original output was so I'm not sure if this really _fixes_ it, or is just a band-aid.
Adding AJAX to the web interface
need to explore CherryPy & websockets, but this quick'n'dirty is a big
speed increase
Merge pull request #346 from OliverEngineer/experimental

attempting fix for issue 305
Update webinterface.py

oops! :'( web/css/style.css
Merge pull request #347 from OliverEngineer/experimental

Update webinterface.py
Fix abort in wxColour_helper on OpenSUSE

This replaces "" strings that cause aborts in python-wxWidgets wxColour_helper with
Python None objects. This corrects an abort where the helper tries to fetch the
first byte of the colour string even when it's 0 length.
Merge branch 'experimental' of git://github.com/kenaaker/Printrun into experimental
Merge pull request #350 from kenaaker/experimental

Fix crash on SUSE when setting temperature due to setting temp field background color to "".
Merge branch 'experimental' of https://github.com/kliment/Printrun into experimental