Big set of Warlock Changes

[Quark]

Some Warlocks went berzerk after testing the new Ruin, and this was Kalgan's response:

We're trying to accomplish three things for warlocks in 1.8.

1. Improve warlock emergency defense (and yes, the mana cost of Death Coil may need to be lowered... deciding things like this is part of the reason we have public test realms).

2. Reduce a warlock's Shadowbolt spam DPS potential. Currently, a shadowbolt optimized warlock can get drastically higher raid damage than any other class in the game by combining Curse of Shadow, Demonic Sacrifice, Ruin, Improved Shadowbolt, Bane, and lots of +shadow damage and spell crit gear (which can be further exaggerated with Shadow Weaving from a shadow priest or multiple warlocks affecting the target with Improved Shadowbolt). We intend for warlocks to deal very high amounts of damage in a raid, but not drastically more so than other classes.

3. Improve warlock DOT's so that it's less likely that much of the damage will be lost due to combat not taking as long as was assumed when those spells were designed.