Fix assignment trait error with nonliving entities

nonliving entity would throw an error when combat is done.
Also document list.contains
Remove 'flag expired' debug

This debug shows regardless of debugmode, which gets annoying very
quickly
Add a parse tag - the dangerous tag!

<parse:<&lt>player.name<&gt>>
Very dangerous.
Merge branch 'master' of https://github.com/aufdemrand/Denizen
fix missed debug

p@/n@ missing from trigger debug
Add npc.has_trigger[name]

A tag to check if an NPC has a trigger, goes along with the trigger
command.
Show the source script in error messages

Wherever possible at least.
Allow sub-keyed notable names, fixes #818

Escaping is magic.
Merge branch 'master' of https://github.com/aufdemrand/Denizen
add element.before_last

A tag to enhance text control.
Add element.after_last

Where would we be without advanced text control?
Add tag yaml[name].list_deep_keys

A second version of yaml[name].list_keys
Also patch a potential error in the NotableManager
Add tag yaml[name].is_list

A useful tag for when you don't know about the YAML file you're working
with
Rework how yaml.read handles lists

Direct list returns, yippee!
Merge pull request #820 from mcmonkey4eva/master

Pull request for various things