Seems horse model was wrong, it had one extra frame at the end (almost identical to the first frame), which caused our animation playback code to be incorrect in order to accommodate for this.

Side-effect was that two frame animations were completely broken.

Bah.

(ERROR - variable instance_material is undeclared)

Adds a check for the instance when normals are provided as part of the vertices element in the collada file and supplies the normals from there (as per the collada spec). If normals still aren't supplied, this defaults to calculating the vertex normals via Geometry.computeVertexNormals().

Also updated build script to fill in missing dependency (ImageUtils => DataTexture).

Collada files normally name the materials, so this adds the name property to the material and puts that name value into it.

As per discussion in #1256

MD2Character is an object encapsulating character body, multiple weapons and multiple skins as a single entity.

Added note about install location for Linux, as well as noted that the scripts/addons folder should be created if it doesn't exist.

Also improved error reporting in JSONLoader (getting DEPRECATED errors for incorrect URLs was really confusing).

Default computation of morph normals for all models with morphs was taking unnecessary time and memory.

Also made it less resource intensive to recompute morph normals.