Change modelScale to be a single float.

Axial scales where never used anyway.
Clean up math functions a bit, use SSE intrinsics on x64.

Also the Hunk allocator returns 16-byte aligned memory, so that it
can be accessed safely with SSE instructions.
New type transform_t to pass bone data to the shaders.

The transform_t stores a rotation quaternion + scale + translation, which
fits into 2 vec4's, so we need less uniform storage per bone.
Add SSE version of the transformation library.
Change refBones to use the transform_t functions.
Fix math in the GL renderer.
Move model scaling out of the skeleton transform function.

Logically model scaling is performed after skeleton transformation, so
do it in that order in the renderer. Then there's no need to pre-scale
the translation in CG_TransformSkeleton.
Fix model rendering with /r_vboVertexSkinning 0
Use shared transformation function instead of manually recoding it.
Implement IQM models in the GL renderer.
Implement IQM models in the GL3 renderer.

(still without VBO vertex skinning)
Implement IQM culling
Add VBO vertex skinning for IQM models.
Merge branch 'iqm' of github.com:Unvanquished/Unvanquished into iqm
Read texture names from the correct address.
If skin surface cannot be found by name, fall back to applying skin shader like MD5

This ensures backward compatibility with the MD5 skins.
Merge branch 'master' into iqm

Conflicts:
	src/engine/qcommon/common.c
	src/engine/qcommon/q_math.c
	src/gamelogic/cgame/cg_buildable.c
	src/gamelogic/cgame/cg_players.c
Allow a tolerance in determining uniformity of scales in IQM to account for exporter imprecision
Merge branch 'master' into iqm
Add iqm support to weapons and buildables