[INTERNAL] Add ISarosSessionManager without setNegotiationHandler()

Method setNegotiationHandler(INegotiationHandler handler)
will be re-activated when NegotiationHandler is integrated

Change-Id: I2a69ea8b0aff46aa669ed03139ee155109c24247
Reviewed-on: http://saros-build.imp.fu-berlin.de/gerrit/1697
Tested-by: Jenkins CI
Reviewed-by: Arndt Lasarzik <alasarzik@gmail.com>
Reviewed-by: Franz Zieris <zieris@inf.fu-berlin.de>