Custom verbs via scripting

[crankycyclops]

Should support custom verbs via scripts. Not sure how this will work yet, but somehow, we'll register the verb along with a pointer to a function that will execute a scripted function (all verbs go in some game script file?) with a name like verbVerbname. Also, we'll probably want to pull verbs array out of getVerbs function and make it a global in vocabulary.c.

NOTE: these notes are related to the old Trogdor project, which was written in C. The same basic principles should remain the same, though.