Work around a crash bug in Firefox 27.

Fixes #1869
Fix typo.
Remove XPCOM component interface.

Declaring an interface isn't actually required for services that will
only be accessed from JS.
Version bump: 1.15beta2
Updated translations from babelzilla.org.
Version bump: 1.15
Merge branch 'master' of https://github.com/greasemonkey/greasemonkey into issue-1868