add &at escapes

To avoid accidental creation of dObjects from user input (Probably not
an issue, but better safe than sorry!)
Make escape tags return an element

Now we can do weird things like escape.substring[5]:po|ta|to
(To match the similar Math: commit)
Also, clean the ParticleEffect meta.
Add util.date.format[x]

To allow the application of custom date/time formatting

The whole util. tag range needs to be update to a more modern system...
Fix the cooldown command

Setting a cooldown on a player would set it global too... because
somebody forgot that you must break out of switches.
Merge pull request #663 from mcmonkey4eva/master

Pull requests for escapes and metas