Add option to vertexdecoder to expand UVs to floats
Delete the DX9 vertex decoder, use the "GL" one instead (now common)
Move vertexdecoder files into GPU/Common
Jit the most common of the "ToFloat" texcoord conversions
D3D vtxdec: Convert weights and normals to float
Fix some endian-ness in generic vtxdec
DX9: Enable vtxdec JIT, buildfix
D3D vtxdec: Fix nrm stuff
d3d: Fix switching between rendering modes.
Merge pull request #6887 from unknownbrackets/vtxdec-centralize

d3d: Fix switching between rendering modes
DX9: Must turn off vertex caching for software skinned draws
Merge pull request #6870 from hrydgard/vtxdec-centralize

Centralize the vertex decoder