Pack blend index and weight into one ushort per weight.

This reduces memory per vertex for md5 and iqm models by 24 bytes.
Remove unused members of struct vboData_t.
Pack vertex color into four unsigned bytes.

This reduces memory per vertex by 12 bytes.
Use the 4 byte representation for colors when possible

Much of our data starts in this format, and it doesn't make sense to convert it to 4 floats at load time then back to bytes at run time.
Store texure and lightmap colors in 16bit integers.

Also use only one vec4 attribute for both. Saves 4 + 4 bytes
per vertex.
Clean up tangent space calculation code.

We don't need 6 different ways to calculate tangent vectors.
Remove never used text deforms.

I guess they were leftovers from Quake I or II.
Use QTangents to store normals and tangent vectors.

Saves 28 bytes per vertex.
Merge branch 'vertexpack'

Conflicts:
	src/engine/renderer/tr_bsp.cpp
	src/engine/renderer/tr_curve.cpp
	src/engine/renderer/tr_flares.cpp
	src/engine/renderer/tr_local.h
	src/engine/renderer/tr_main.cpp
	src/engine/renderer/tr_model_md3.cpp
	src/engine/renderer/tr_model_md5.cpp
	src/engine/renderer/tr_model_mdc.cpp
	src/engine/renderer/tr_model_psk.cpp
	src/engine/renderer/tr_model_skel.cpp
	src/engine/renderer/tr_sky.cpp
	src/engine/renderer/tr_surface.cpp
Fix lightMapping shader for QTangents.
Fix Deforms.
Audio resource handles: don't try to clear an invalid handle.
Add support for cmake versions less than 2.8.10
Add timings for VM loading
Generate stripped versions of nacl executables
Fix MD3 normals loading.
Fix some light grid issues.
Fix texture coord packing for MD5 models without vboVertexSkinning.
Fix incorrect stride for dynamically computed qtangents.
Allow GPU vertex skinning on Radeon/MESA.

Works for me.