Gcode filemanagement now lives in its own module. Upload triggers gcode analysis, result is stored into metadata file. Print jobs triggered and their results are saved as well. Adjusted UI to display gcode analysis result and last print date and (color coded) result if available. Also adjusted gcode file list to color code entries according to last print result.
Fixed exception triggered on analysis abort
Initial gCodeViewer (http://github.com/hudbrog/gCodeViewer) integration
Initial implementation of autoupdate gcodeview on status from server
Auto-load file on connect; some refactoring
Bug: octoprint deleted all commented lines, now gcodevisualizer deletes them too so the line numbers match
gCodeVisualizer can be enabled as a feature in config now (enabled by
default)
Some cleanup from initial integration: removed separate icon for viewing gcode
Fixed some residual stuff after rebase
Remove duplicate css files
Revamped gcode analysis.

Now UI and backend take data from saved metadata (if available). Metadata gets written after file upload and also on startup (for files that have not been added yet). Gcode analysis is interrupted if a printjob is started and resumed when it ends. Frontend is notified when new metadata comes available and UI triggers reload of gcode file list.  Also started on implementing proper logging.
Merge branch 'gcodeViewer' into devel

Conflicts:
	octoprint/server.py
	octoprint/settings.py
	octoprint/static/js/ui.js
First version with gcode viewer integration.

Did some minor changes: renamed gcode tab, renamed gcode file download endpoint, added some margin for gcode viewer accordion. Not sure yet what to do about the gcode viewer controls/settings, until I figure this out they'll stay where they are now ,)
Added gcode viewer setting to the README