Merge pull request #83 from jlewin/development

Switch to async file dialogs
fixed the colors to match the last release.
Made the export multi material work for more than 2 extruders.
Made the parts that are outside the extruder count map to extruder 1.
changed the thumbnails to save as png rather than tga (less than 1/10 on average).
Working on cleaning up cache data.
Changed names of preview release options to 'Alpha' and 'Beta'.
Making the thumbnail bath info easier to get.
Don't show touchscreen options for now.
Add ability to reload theme without switching it.
Merge branch 'development' of https://github.com/MatterHackers/MatterControl into development
the x between the controls was ambiguous. Changed it to a space.
put back in the hardware has_ settings.
Made the progress info in View3D go through our code rather than bacground task.
put in some diagnostics
Better update messages.
fixed text color on export to sd
oops. don't turn of trace generation.
Fix language of confirm message box.
'Print' action in Library and History now initiates print - if possible.
Merge branch 'development' of https://github.com/MatterHackers/MatterControl into development
Only fire OnConnectionSucceeded if connected
Ensure connect buttons reflect active state when (re)loaded
Improve Connect button enable/disable logic