generice, and also more in line with the rest of quake's clipping system
(ie, support the entity size selected hulls). I'm not /entirly happy with
what's here, but it's a start, and the force fields in customtf work /much/
better :)
add a crc field to aliashdr_t
model_alias.c:
set it for all models
cl_parse.c:
set the pmodel and emodel info keys to the crcs of the player and eye
models
