Changed how tr_stencilshadow.cpp works by convuluting all the
static variables into a struct for access via pointers.
changed LIGHT_CLIP_EPSILON into a double and made it local to tr_stencilshadow.cpp and interaction.cpp.
cleaned out old unused code from tr_stencilshadow.cpp.
changed the error in one of the deform functions in tr_deform.cpp to a warning and to not draw anything if it fails.

Signed-off-by: ralph engels <ralphengels@gmail.com>