fsrawconference: Make the construction more consistent
fsrawconference: Make the construction more consistent

In the construction of a raw session we add a bunch of elements. For all
elements unref them in _constructed if adding them to the bin fails, for
all other failures, leave it to the _dispose function to remove and
unref the elements

pexip/farstream,kakaroto/farstream,kakaroto/farstream,tieto/farstream,pexip/farstream,kakaroto/farstream,tieto/farstream,tieto/farstream,tieto/farstream,shadeslayer/farstream,shadeslayer/farstream,pexip/farstream,shadeslayer/farstream,shadeslayer/farstream,pexip/farstream,kakaroto/farstream,tieto/farstream