SL-375, SL-378 - rudimentary logging info to list joint offsets during mesh import. dae_tool.py work to enable joint offset tweaking.

SL-344 - fixed a problem in avatar_lad with some params in wrong group, added diagnostics to make this easier to detect.

SL-374 - don't allow sliders to modify joint positions if there's already a mesh-imposed override in place.

SL-314 - show bones now colorizes rigged-to joints a different color. Also removed what I think is some redundancy in calculating attachment pos overrides. If it breaks I'll change it back.

SL-371 - increased the limit for StackWalker strings, avoid crashing if mesh has wrong number of mAlternateBindMatrix matrices

SL-109 - reduced size of the spheres in 'show bones' display, to make it easier to see what's going on in crowded parts of the skeleton.

SL-338 - added --set_version to anim_tool.py, for creating files to test upload of unsupported file versions.

SL-362 - changed 'could not link driven params for wearable' into a debug message. Needs more diagnosis to figure out whether we care. Silencing for now to avoid redundant bug reports.