Update to 1.6.4
Ignore list and no tpa to self. Fixes ESS-4456 ESS-4711

List users that you ignore when no arguments are given. Otherwise state
that no players are ignored.

Don't allow users to tpa or tpahere themself. This is a problem with
people "glitching" with how essentials finds a safe location to get
inside of places they shouldn't.
Format to the format with the formatter.
Adds clarification to metrics opt-out
Adds even more clarification to metrics opt-out
Extract user match looping
Add more API template and implement nick change event.
Improve nick validation
Now matches nicks against userdata for conflicts
Now checks for empty string nicknames
Cleanup
Allow recolouring own name.
Update README.markdown
Implement a couple events