fixed several bugs in bots to do with movement and aiming

fixed several bugs in bots to do with movement and aiming
optimized ctf and keyhunt by keeping flaglist and kh_keylist variables
(greatly accelerated some code that used find before)
added bot_ai_thinkinterval 0.05 which means that fast servers don't
croak from bot ai
added bot_ai_dodgeupdateinterval
added bot_ai_chooseweaponinterval
added bot_ai_dangerdetectioninterval
added bot_ai_dangerdetectionupdates (how many waypoints to update danger
ratings on per interval)

git-svn-id: svn://svn.icculus.org/nexuiz/trunk@3426 f962a42d-fe04-0410-a3ab-8c8b0445ebaa