Print "end" to clipsort.log in wahjamsrv

The client prints "end" before closing clipsort.log so do it in the
server too.

Signed-off-by: Stefan Hajnoczi <stefanha@gmail.com>
Add wahjamsrv clipsort.log "interval" statements

Commit ec33d851430f2d271404c8abc8dca0d252e21000 ("Remove interval count
from User_Group") dropped the wahjamsrv clipsort.log "interval"
statements.  Add them back in using a QTimer to trigger interval
changes.

Signed-off-by: Stefan Hajnoczi <stefanha@gmail.com>
Only begin session recording when 2 users are on

Signed-off-by: Stefan Hajnoczi <stefanha@gmail.com>
Add User_Group userAuthenticated() and userDisconnected() signals

Add signals on successful authentication and on disconnect.  The Server
class will be able to use them to start/stop sessions more
intelligently.

Signed-off-by: Stefan Hajnoczi <stefanha@gmail.com>
Start recording session when 2 users have authenticated

Hook up to User_Group::userAuthenticated()/userDisconnected() signals in
order to start/stop session recording immediately.  This allows us to
get rid of the arbitrary 30 second session idle timer.

Signed-off-by: Stefan Hajnoczi <stefanha@gmail.com>