Fix #42 Refer-To header is duplicated

Refer-To header is duplicated and Max-Forwards is missing on transfered
calls
Revert "Fix #42 Refer-To header is duplicated"

This reverts commit 28ee434f85e82b3416f9bab16460831c85f34793.
Merge remote-tracking branch 'origin/master' into 1.3
Fix #43 - INVITE request for parallel forking is discarded

Added Via header branch matching on the initial transaction
Fix #44 - Re-INVITE without SDP is discarded

Allow INVITE without SDP for the first scenario to resume a call on hold
The second scenario for media re-negotiation is still open
Fix #45 - 200 OK response to OPTIONS without resources

The xcoder_b2b now checks for the connection to xcoder and monitors the
number of errors during call setup
Depending on the above it will not answer 200 OK to OPTIONS and will
reject INVITE requests
Merge remote-tracking branch 'origin/1.3'