add inventory.contains.material[mat]

a quick tag for https://github.com/aufdemrand/Denizen/issues/554

Also add a missing Chat command argument
Add dEntity.tame mechanism

Just a quick mech to tame entities.
... mechanisms need quite a bit of cleaning. Will do that soon if not
done by someone else first.
Fix - playeffect effect:random

... how long was this broken?
Either way, tested and working fix.
Fix - playeffect effect:random

... how long was this broken?
Either way, tested and working fix.
Merge pull request #559 from mcmonkey4eva/master

YAPR.