Reduce memory footprint of Creature

This commit also optimizes Player::getCorpse() and Monster::getCorpse().
It also fixes a bug where a player could get an unjustified kill after
justifiedly attacking a player.
Code cleanup
Fix bug with condition end time

This commit fixes issue #288
Added new valid looktypes to looktype.lua
Merge pull request #290 from ninjahopparn/master

Update looktype.lua