Don't fill the spellbook with missing spells before compiling new script.

Don't fill the spellbook with missing spells before compiling new script.

Before this change, the spellbook (OvaleData.spellList) would be populated
with entries found from a previous script compilation, which may have
changed after the event SPELLS_CHANGED is received.

This change makes filling the spellbook with missing spells found in the
script happen *after* the script is compiled, and moves the responsibility
into OvaleCompile:Compile().

git-svn-id: svn://svn.curseforge.net/wow/ovale/mainline/trunk@681 d5049fe3-3747-40f7-a4b5-f36d6801af5f