Fixes #1241: Removed disposition-based combat conditions

The information for this code came from UESP, which in turn cites a (extremely vague) section from the TES-CS help text, so no surprise that it wasn't accurate.

The guard on the boat has a fight rating of 70, so with the old code it would attack on sight if the disposition is low enough. BTB-Character.esp includes something (not sure what) that drops his disposition to 35 when playing as a Khajiit, making him attack.

Testing in Vanilla it appears that disposition has no effect on combat engagement at all. Even with disposition 0 and fight 70 the NPCs don't attack.

Setting an NPCs fight rating to 70 or less still has a meaning, because the higher it is, the easier it becomes to raise the fight rating to 80 (by taunting, for example).