added check for minimal quad size to avoid divisions through zero (closes #487)
disallowing quads with an empty area altogether (refs #487)
now avoiding clipping of native filter bounds (closes #481)
optimized performance of 'normalizeAngle' by avoiding loop (closes #488)
added 'destroyBuffers' so that batch doesn't destroy every time capacity is changed
optimization of 'removeEventListener' (refs #491)
replaced the last 'removeEventListener' optimization with a better one (closes #491)

Previously, I overlooked the side-effect of "splice" (always allocates two new objects).
fixed invalid vector initialization (closes #491)
fixing null reference exception introduced in last commit
Merge remote-tracking branch 'upstream/master'

Conflicts:
	starling/src/starling/display/QuadBatch.as
Merge branch 'master' of https://github.com/Varnius/Starling-Framework