release: update for 1.8.13

git-svn-id: https://svn.resiprocate.org/rep/resiprocate/branches/resiprocate-1.8@10446 ddefafc4-47db-0310-ae44-fa13212b10f2
resip/stack: error gives hint about missing intermediate cert

git-svn-id: https://svn.resiprocate.org/rep/resiprocate/branches/resiprocate-1.8@10448 ddefafc4-47db-0310-ae44-fa13212b10f2
release: update ChangeLog

git-svn-id: https://svn.resiprocate.org/rep/resiprocate/branches/resiprocate-1.8@10449 ddefafc4-47db-0310-ae44-fa13212b10f2
resip/rend: fix EXTRA_DIST

git-svn-id: https://svn.resiprocate.org/rep/resiprocate/branches/resiprocate-1.8@10453 ddefafc4-47db-0310-ae44-fa13212b10f2