Add missing directories to DOMAIN_METHODS for javascript (bug 844591)

https://bugzilla.mozilla.org/show_bug.cgi?id=844591

Extractor wasn't considering `media/js/devreg/` and `media/js/common` so if you had not run `compress_assets`, it would never pick up strings in those directories. The missing one mentioned in the bug was in `devreg/`.