Bug 415491, part 1 - Make UnEscapeURIForUI escape the URI if it contains any 'network.IDN.blacklist_chars' characters (except space).  r=bzbarsky
Bug 415491, part 2 - Implement a char16_t version of NS_EscapeURL.  r=bzbarsky
Bug 415491, part 3 - Use NS_EscapeURL of _retval as the result.  r=bzbarsky
Bug 415491, part 4 - Make UnEscapeURIForUI always escape the result if it contains blacklisted characters.  r=bzbarsky