Fixed duplication when dragging media into the backpack
Fixed incorrect caching in primVarSet and primVarChange
Fixed dragging "when Stage clicked" into a sprite
Merge pull request #177 from nathan/set-var-cache

Fixed incorrect caching in primVarSet and primVarChange
Merge pull request #174 from nathan/backpack-duplicates

Fixed duplication when dragging media into the backpack
Merge branch 'fix-stage-sprite-clicked'

Conflicts:
	src/blocks/Block.as
Switched to a ternary conditional