ML: changed how connection messages time out (pmtu timeouts)
connection messages are sent in UDP and also double as PMTU discovery.
Except for INVITE, losses were not handled. Now they are.
PMTU was assumed to be symmetric. Now it is not assumed anymore.
git-svn-id: https://repository.napa-wine.eu/svn/napawine-software/trunk/GRAPES/ml@797 c54fac2e-1815-407e-9b96-088d06743913