A bunch of stuff again.

* Lock on targets bob now, and are used for CA_HOMINGTHOK and SH_ATTRACT as well.
* Flag stuff is now animated like it was designed to be but which was kinda messed up.
* Cork sounds.
* P_SpawnLockOn(player_t player, mobj_t lockon, statenum_t state) for Lua.
* Added homing/firing CA2_GUNSLINGER stuff at egg guard shields.
* Fixed homing stuff wrt egg guard shields and sea egg balloons.
* Fixed attract orb goin' gold when doing a CA_HOMINGTHOK homing ability.
* Fixed positioning of player during homing attack.
* Cleaned up lockon spawn code.