Consolidate delta validation to cl_parse.c, removing player state delta validation from cl_view.c.
About halfway to using cached matrices for collision detection. Implemented on client side, and cleaned up server side quite a bit. No more link_t garbage; use GList to manage entities in sectors (like Q3) -- avoiding confusing reuse of term 'area'.
Move g_link_t into server-private sv_entity_t. Next step is to update the sv_entity_t matrics on Sv_LinkEdict, and then use those for all Cm_PointContents / Cm_Trace invocations.
Complete the refactoring of Cm_TransformedBoxTrace and Cm_TransformedPointContents to accept clipping matrices for each entity. Traces and contents checks no longer require calling AngleVectors for each rotated entity.