Firefox 50.0 has been released on Nov 15th. Please see https://www.mozilla.org/en-US/firefox/50.0/releasenotes/ for the release notes.
Thank you for the bump request, but please wait at least 48h next time.
The mozilla team knows instantly, about new releases, but a complicate package like mozilla requires lots of man power.
If you can provide help, have a look at:
Bug #599924 is a dup. Thanks Gentoo devs for your effort.
*** This bug has been marked as a duplicate of bug 599924 ***