Changed the way sub-spells are handled

Meta spells that define sub spells can now list options on those sub
spells, such as cast mode, power, and delay. For example:

spells:
- pain(mode=partial power=1.5 delay=10)
- morepain(mode=full power=0.5)

Valid modes:
- direct: the sub spell's effect is called directly, no other processing
is done
- partial: some processing is done, such as modifiers and variables
(this is the default)
- full: full processing is done, including cooldowns, reagents, and cast
messages
- hard: the spell behaves like a hard-cast, as if the player had casted
the spell with a wand item (this loses targeting info)