(CE-615) Cleanup i18n in WikiaNewFiles

Cleanup i18n in WikiaNewFiles in preparation for review by TWN.
* Add wikianewfiles-title to i18n file, which is used in the
  WikiaNewFiles.class.php but was defined in our main messages file
  for some reason.
* Corrected escaping of messages being outputted as HTML, and remove
  instance of double escaping.
* Fix message that was still using old wfMsg options as a second
  parameter which resulted in "older parsemag" and "newer parsemag"
  as the output rather than the correct number
* Add GENDER support to wikianewfiles-uploadby
Merge pull request #2835 from Wikia/CE-615

(CE-615) Cleanup i18n in WikiaNewFiles