Was adding each face with a remove doubles option that made conversion increasingly slower for larger meshes, this would often hang blender when starting with the BGE with larger meshes.
Replace btTriangleMesh()->addTriangle() with btTriangleIndexVertexArray()
YoFrankie level_1_home.blend starts a third faster, level_nut about twice as fast.
- previous commit was also incorrect using the original meshes vert locations rather then the vert locations that came from the derived mesh.
- Softbody is relying on removing doubles at 0.01 to give stable results, this no longer works but seems a bit dodgy anyway. Maybe some post-processing filter could fix up a mesh for bullet softbody.