- added mesh_get_texspace (should be used instead of direct access)

which calculates texspace on demand if need be.
 - removed almost all calls to tex_space_mesh

There may be a few corner cases where this goes wrong (meshes with vertex
keys) but these should get ironed out by coming modifier system.

source/blender/python/api2_2x/NMesh.c

@@ -305,7 +305,6 @@ vertex coordinatess.\n";
 void mesh_update( Mesh * mesh )
 {
 	edge_drawflags_mesh( mesh );
-	tex_space_mesh( mesh );
 }
 
 /*****************************/