Bug in message framing detection

[bennylp]

For TCP, if the remainder of a message contains garbage, it will cause the next valid message to be discarded. For example, consider the following:

INVITE sip:user@company.com SIP/2.0
To: sip:j.user@company.com
From: sip:caller@university.edu
Call-ID: 0ha0isndaksdj@10.0.0.1
CSeq: 8 INVITE
Via: SIP/2.0/TCP 135.180.130.133
Content-Type: application/sdp
Content-Length: 138

v=0
o=mhandley 29739 7272939 IN IP4 126.5.4.3
c=IN IP4 135.180.130.88
m=audio 49210 RTP/AVP 0 12
m=video 3227 RTP/AVP 31
a=rtpmap:31 LPC/8000
asdpasd08asdsdk:;;asd
 a0sdjhg8a0''...'';;;;

With current parsing, the garbage will be prepended to the next message, and it will cause the parsing of the next message to fail.