Move a large amount of botlib game AI to game VM!

Moved ea, goal, move, weap, and weight from botlib/be_ai_* to game/ai_* !

Added and removed a bunch of game system calls.
Added base directory argument to trap_PC_LoadSource, needed for loading bot item and weapon files.
Added PC_ReadStructure (which requires some 400 lines..) to bg_misc.c based on botlib code.

Botlib's BotExportTest function is now broken, though it isn't ever compiled.
Clean up my botlib to game helper functions/defines
Remove unused Vector2Angles from botlib and bspc
Remove trap_ prefix from EA_* calls

EA_* are in game VM now.
Remove trap_ prefix from bot move AI
Remove trap_ prefix from bot goal AI
Remove trap_ prefix from bot weapon AI

Put back some comments in ai_weap.h too.
Update game/ai_* file headers (we're not in botlib anymore)

And we're not ai_chat.c either, strangly enough.