Split Button Implementation:
Added DynamicDropDownMenu( can add to drop down via .add method)
DropDownMenuWidget (made drawDirectionalArrow virtual)
Added Factory for DropDownMenu and Split Button
Add/used Factories in View3DWidget
Fixed thumbnail rendering issue on Linux
Did a bit more work to prove out the settings design.
Merge pull request #106 from gregory-diaz/development

Fixed thumbnail rendering issue on Linux
Made the return to position on un-pause also work for user request pause from click 'Pause' button.
Set the extruder speed to something reasonable
Working to put in z transform control, and much more intuitive controls longer term.
Made it possible to have no selection.
Put in an option to set the extruder to use for the raft.
New raft localization.
Made the upArrow a separate class and making it use the InteractionVolume base.
Merge branch 'development' of https://github.com/MatterHackers/MatterControl into local_development
Getting the up arrow to know its own state.
Make it easier to get a tranable from a mesh.
Make the z arrow show hover state.
turn off the up arrow for now.
Cleaned up the drop down settings menus to work well.
Got rid of some crash problems with no selection.
Make sure we don't crash when nothing is selected in any of the edit tools.
more work on interaction volumes
Upgrading to .net 4.5.
Took out some dead code.
Fixed the printer looses temp after starting a print.