Bug 840814: Redirect bad whatsnew and firstrun URLs.
Merge pull request #662 from pmclanahan/bug-840814-redirect-bad-firstrun-whatsnew-pages

Bug 840814: Redirect bad whatsnew and firstrun URLs.
Bug 840814: Also redirect incorrect firstrun|whatsnew URLs without locale.
Merge branch 'bug-840814-redirect-bad-firstrun-whatsnew-pages'