Dark Pact range fix

Dark pact no longer has meaningful range (or line of sight) restrictions on the PTR. This is another kick in the nuts for life tap affliction, but also a very important change if dark pact is going to be a consistent contender as a raid spec in cataclysm. The general theme of the next expanion means we can likely expect a lot more dragons, and that's the main type of boss where that 30 yard limit becomes a serious issue.