s4:imessaging: Remove event context from irpc and imessaging structures

s4:imessaging: Remove event context from irpc and imessaging structures

The only part of this code with a stored event context is now the
binding_handle created by irpc_binding_handle() when in the client
dcerpc_binding_handle_set_sync_ev() is called,
otherwise a new nested event context is created for sync calls.

Note that the FD event associated with the socket still implies
the long term event context passed to imessaging_[client]_init().

Andrew Bartlett

Change-Id: I9aeae94b26e3736370f449daa96808e6cdc2d55d
Signed-off-by: Andrew Bartlett <abartlet@samba.org>
Reviewed-by: Stefan Metzmacher <metze@samba.org>
Autobuild-User(master): Stefan Metzmacher <metze@samba.org>
Autobuild-Date(master): Tue May 13 02:33:24 CEST 2014 on sn-devel-104