Add coop on/off functionality

[Endernice61]

Added enum for player teams in portal_man.nut
Added PortalGun class to store information about what portals the portal gun can shoot with method to apply it to an actual weapon_portalgun
No longer waits 2.5 seconds to find players as this method does not work for published maps
Added on_blue_spawn() and on_oran_spawn() which gets called by trigger created by compiler (see here). Calls _find_players() once both bots have spawned for the first time, or sets that bot's portal gun's keyvalues if that bot has already spawned.
_find_players() will now call in_hover_phase(), which waits until bots are able to move, then calls on_blue_spawn() and on_oran_spawn() to set up portal gun keyvalues
init(blue, orange, has_onoff initializes PortalGun classes for both bots
return_pgun() will set the bots' portal gun's keyvalues
Added set_gun(pgun, team) to set a bot's portal gun to match pgun
pgun_btn_deact() and pgun_btn_act() now update bots' portal guns
Added set_pgun_keys(gun) to set keyvalues on spawned portal guns in singleplayer