Change internal implementation of spell lists.

Change internal implementation of spell lists.

Move internal representation of spell lists from lists whose values are
the spell IDs to tables indexed by spell IDs with a default value of
"true".  This makes it easier to do the most common operation, which is to
check whether a given spell ID is in the spell list -- we can now do a
simple table lookup instead of walking the list.

git-svn-id: svn://svn.curseforge.net/wow/ovale/mainline/trunk@930 d5049fe3-3747-40f7-a4b5-f36d6801af5f