[Feature Request] Promote Cata pseudo-stats to real stats, with appropriate stat mods

[raethkcj]

For the initial Cata launch, StatLogic.Stats.SpellPower will remain split in its Vanilla-Wrath forms of SpellDamage and SpellHealing.

StatLogic.Stats.ManaRegenOutOfCombat will just be a translation on top of ManaRegenNotCasting.

Sometime post-launch it would be good to sort these out into real stats with per-expansion dependencies.

[raethkcj]

Note: The Feral Druid talent Nurturing Instinct appears to be the only stat dependency left in Cata that provides just SpellHealing; everything else provides both SpellDamage and SpellHealing, so could be converted to SpellPower.