Stop multi-aggro on room entry, and allow players to regen health before moving in response to monsters aggroing before players take an action.

Multiple monsters were aggroing on entry occasionally due to room.kod resetting the player's chaser level (amount of monsters chasing him basically). Monsters can now act before a user makes a move, therefore we need to remove this call as it resets the chaser level AFTER the player gets aggro, which means another monster can then aggro also.

Since monsters can attack before a first move in some cases, players should gain health here too. This will mean occasionally a player can log off/on and sit still to regain health without aggro, however this is risky because the monsters *can* respond sometimes.