add french to config

add french to config

a couple of bug fixes in mongo db

ios ru translation

a bit more work on Helping out section

change /status path to /debug/status

a few benighn lint warnings fixed

fix for tinode/webapp/issues/78

Merge pull request tinode#660 from tinode/fixes

Send 'sub' push notifications when user joins a group.

Merge branch 'devel'