[2844] Implement some missing doors in Utgarde Keep

Conflicts:
	scripts/northrend/utgarde_keep/utgarde_keep/boss_ingvar.cpp
	scripts/northrend/utgarde_keep/utgarde_keep/instance_utgarde_keep.cpp
[2846] Cleanup some scripts ported to eventAI
[2848] Implement achivement Lightning Struck - Halls of Lightning

Also cleanup the style of the instance
fix some problems from last commits