Allow arbitrary-length splitter in get_sub_items

Allow .split_by[&co] instead of just .split_by[&]
Add ~break (wait-for the NPC to break something!)

- can now use ~break, similar to ~walk or ~run
- also fix the meta of the 'Spawn' command and an automated warning that
bugged me.
Add context.location to the EntitySpawn event

- <context.location> is a base necessity!
- Also, add some more debug warnings
Merge pull request #688 from mcmonkey4eva/master

Pull request for arbitration and anti-arbitration