Added Zero Checking prior to decrementing the currentNodeIndex.

This change prevents the node index from going negative and will allow
execution to continue instead of a hardware exception which stops the
output controller.
Fix Nutcracker backwards megatree.
This change removes the reversing of the x direction in Nutcracker.cs and NutcrackerEffectEditor/NutcrackerTypeEditorControl.cs. Instead it fixes the (probable) reason they were added:  and fixes the reason they were added which (imho) is that PreviewMegaTree::Layout was setting up the 'lines' based on the X coords coming back from GetEllipsePoints.  These come back in decreasing x values.  The fix is to just reverse the order we pick them up in.
I like this version of the fix to PreviewMegaTree a bit better.
Merge remote-tracking branch 'upstream/master'

Conflicts:
	Modules/Effect/Nutcracker/Nutcracker.cs
Reuse the collection to reduce object creation. Method is called for every state update.
Merge remote-tracking branch 'remotes/komby/master'
Merge remote-tracking branch 'remotes/jeffu231/master'
Merge Bill's fixes for the Nutcracker 'backwards megatree' issue (merging his and Derek's work). Still has debugging stuff enabled.
Remove some debugging messages from the nutcracker effect.
Avoid crash when playing a sequence if the mp3 file is missing.  This change allows Giz's sequence to play even though I don't have his audio file.
Merge branch 'master' of https://github.com/sall/vixen into sall-master
Merge branch 'sall-master'

Conflicts:
	Modules/Effect/Nutcracker/Nutcracker.cs
Combine intents when there are multiple intents side by side with the same/similar information...