Revert "Add RTCW's trap_R_GetSkinModel to cgame/ui"

This reverts commit 762f53fbc499317176c684b7bf6f2e4d05b9f370.
Skip RTCW/ET skin models and playerscale in skins

Cgame can load the file and get the info itself. New games should use a separate file if want more keywords.

Also, lets completely skip tag_* lines. Otherwise creates a surface for whatever is after tag_*.