Fix bug 1066655: FxA registration should update FxA specific lang field.
Merge pull request #104 from pmclanahan/fxa-lang-new-field-1066655

Fix bug 1066655: FxA registration should update FxA specific lang field.
Add fxa_id to subscriber admin.
Fix bug 1067563: Require accept_lang instead of lang

For Firefox Accounts registration.
Remove FxOS workaround now that bug 962225 is fixed.