Added SessionState to Session
added DisconnectUserSession Call. Extends SessionStore
added logoff call.
added logoff call part 2.
add logoff call part 3
icp: fixed typo in DisconnectUserSession
session-manager: don't stop on cmd line input

On Linux/Unix use signals to stop instead of terminal input
rds: don't shutdown on sigpipe
rds/icp: stubs for disconnect and logoff added
fds: send disconnect message to session-manager

Inform session-manager when a client has disconnected from a
session
mod/x11: allow multiple connections to service pipe

Only the first conect to the service pipe was working. Further commits
didn't get accepted.
mod/x11: connect framebuffer on client accept

Check if the framebuffer is already connected if a new client
is accepted on the pipe.
rds: update whole display on connect/disconnect

If a client connects make sure the complete display is sent out once otherwise
display might initially not be show correct.
Merge branch 'master' of github.com:bmiklautz/FreeRDS