Fix error dialog being displayed in a headless context.

This was causing an infinite cycle of java.awt.HeadlessException in case handleError was called in an environment without display.
Add Screen blend mode.
Update javadoc for screen blend mode.
Screen blend mode for JOGL.
Screen blend mode for andriod.
fromIntARG and fromIntRGBA now returns self.
Move update logic into DefineList.
Revert back to merge sort for geometry sorting.
Some issues have been reported, and are difficult to track as they happen randomly.
Update .gitignore with more build and nbproject/private folders
Make sure to throw exception if trying to use instancing but its not supported
Revert 04f8956
The inconsistent compare function errors are due to user error, not engine error.
Add test to trigger the inconsistent compare function detection in the sorting algorithm.
It modifies a texture on a material from another thread, which changes the material's sort ID,
thus causing the OpaqueComparator's compare method to violate the compare method contract.
Change the compare function error in ListSort to be more user friendly and indicate the likely cause of the error.
Change the compare function error in ListSort to be more user friendly and indicate the likely cause of the error.
TestInconsistentCompareDetection: Make sure we have more than 128 geometries in our scene graph to actually trigger the compare error
Merge pull request #172 from kwando/master

Move update logic into DefineList.
Fix crash in TestInstanceNode (do you guys even test??)
Merge pull request #168 from kwando/color_changes

fromIntARG and fromIntRGBA now returns self.
Merge pull request #155 from blay09/bug/handleerrorheadless

Prevent error dialog from being displayed in a headless context
Merge pull request #126 from kwando/screen_blendmode

Add Screen blend mode.