Mateos Classic Frames

Fixes for World of Warcraft: Forever, which hides health, power and other combat numbers from addons.

- Fixed the Lua error in health and power text ("attempt to perform arithmetic on a secret number value").
- Percent text, incoming heals, cast bars, combo points, auras and totems now work with the hidden values.
- Buffs and debuffs are hidden instead of erroring when the game won't let addons read them.
- The threat percentage is hidden when the game hides threat; use Forever's own threat display then.