Add some high-power debugging to chat triggers

Just placeholders for when we need to investigate chat trigger trouble
Minor code cleaning, deprecation

no need to check dCuboid.matches, we already know we're trying for a
cuboid. Also, deprecate old doEvents methods with the intent of
switching to new List-based events.
De-stupid how flag setting works

If no index is given, we obviously want to set the whole flag, not part
of it.
Catch invalid location.distance tags

and fail cleanly
Don't duplicate in context.cuboids

I declare a formal "woops" on behalf of whoever wrote that bit of code.
Shut up null errors in entity teleports

also patch meta
Add chunk.spawn_slimes

I have no easy way to test this SO ENJOY
Fix typo
Merge pull request #889 from mcmonkey4eva/master

Pull request for final 1.7 build