EXT-8135 FIXED Textures blurry when in Appearance Edit mode

EXT-8445 Reduce baked texture timeout fro 120sec to 60sec default

Also did some minor infrastructure cleanup, added code comments, etc.  There is now separate logic for determining how to handle update (versus upload) requests.
Also made a trivial change to llvoavatar to properly encapsulate mAppearanceAnimating.
Also reduced the baked texture timeout to 60s (in settings.xml)