Update CSP addon.

* Fix quoting issue with `self` and `none` default values (they must be
  quoted but they were not previously).
* Enable `unsafe-eval` when running in development environment. Required
  for use with `wrapInEval` (which defaults to "on" when running in
  development mode).
Merge pull request #2141 from rwjblue/update-csp-addon

Update CSP addon.