Minor: Cleanup in CGTextureMapping.cpp

Some minor syntactical cleanup:

• Condensed all `info` point coord assignments and UVs coord assignments into a line for each in cgTextureMappingBlit<>().
• Condensed plain-C cgTextureMappingBlit() to C++-templated cgTextureMappingBlit<>() branching functions by putting all args on one line, hanging the function-opening and switch `{`s, in-lining each return with each case, and removing the blank line between each.