Drop setting the energy/rage/focus parameter for spells.

Ovale already looks up how much power a spell costs every time it runs
the script.  Only use the energy parameter when we need to override the
return value of GetSpellInfo (rarely) or for spells that add power.
Reorganize file layout to simplify adding more scripts from contributors.

Scripts are broken down by class and each file name is named for the
contributor.
Add feral/guardian script contributed by @ShmooDude.

Script from "Leafkiller's MoP Feral/Guardian Ovale Script" on the Fluid
Druid Kitty DPS forums:

  http://fluiddruid.net/forum/viewtopic.php?f=3&t=857&p=18073#p18066