From a very early time, we had a few things that Djblets monkey-patched

into the standard String class for JS code. This change gets rid of the

use of those in the RB codebase:

String.trim() is a standard-library method that does what our

String.strip() method did.
_.escape() and _.unescape() do what our String.htmlEncode() and

String.htmlDecode() methods did (plus are slightly more complete).
String.stripTags() was only used in one place, which was already

  doing some regex transformations, so I've just moved the

  implementation of that into where it's used. We don't use that option

  at all, though, so perhaps we should just remove it from the inline

  editor too.
String.truncate() wasn't used anywhere.

Ran js-tests.