gl_Texcoord[]/gl_Color should be explocitly passed as in/out.
Compilers can pack varyings if the architecture does benefit from it (for instance intel mesa driver) but on the other hand they usually don't change size of varying even if there is only a single component used.
So storing vec2 into vec4 may waste performances.
git-svn-id: svn+ssh://svn.code.sf.net/p/supertuxkart/code/main/trunk@14974 178a84e3-b1eb-0310-8ba1-8eac791a3b58
