PowerCost calculation is being done in 2 places: Power.ts (function PowerCost) and Data.ts (function GetSpellInfoPropertyNumber).

This is to support things as:

• add_rage
• add_rage_from_aura
• rage_percent
• refund_rage
• max_pain

but also

• add_cd
• cd_percent
• add_duration
• duration_percent

We should refactor so this is done in 1 place, without causing circular references between Power, Aura and Data.

Check 46a7a77 for some more insight