rewrote server sendstates building code, no longer builds two

rewrote server sendstates building code, no longer builds two
entity_state_t arrays (where one of them is global and one per-client),
this is a slight efficiency loss but saves a few megabytes and makes the
customizeentityforclient code more straightforward
merged some global variables into cl. and sv. structs, and others became
arrays on the stack

git-svn-id: svn://svn.icculus.org/twilight/trunk/darkplaces@7243 d7cf8633-e32d-0410-b094-e92efae38249