astobj2: Remove OBJ_CONTINUE support.

OBJ_CONTINUE was a strange feature that came into the world under
suspicious circumstances to support an abuse of the ao2_container by
chan_iax2.  Since chan_iax2 no longer uses OBJ_CONTINUE, it is safe to
remove it.

The simplified code should help performance slightly and make
understanding the code easier.

Review: https://reviewboard.asterisk.org/r/2887/
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Merged revisions 399937 from http://svn.asterisk.org/svn/asterisk/branches/12


git-svn-id: http://svn.asterisk.org/svn/asterisk/trunk@399938 f38db490-d61c-443f-a65b-d21fe96a405b
chan_sip: Reject calls on 200 OKs if no SDP has been received

When Asterisk receives a 200 OK in response to an invite, that peer should have
sent an SDP at some point by then. If the channel has never received an SDP,
media won't have been set and the remote address won't be known. Endpoints in
general should not be doing this. This patch makes it so that Asterisk will
simply hang up a call if it sends a 200 OK at this point. So far this odd
behavior for endpoints has only been observed in tests which involved manually
created SIP transactions in SIPp.

(closes issue ASTERISK-22424)
Reported by: Jonathan Rose
Review: https://reviewboard.asterisk.org/r/2827/
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Merged revisions 399939 from http://svn.asterisk.org/svn/asterisk/branches/1.8
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Merged revisions 399962 from http://svn.asterisk.org/svn/asterisk/branches/11
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Merged revisions 399976 from http://svn.asterisk.org/svn/asterisk/branches/12


git-svn-id: http://svn.asterisk.org/svn/asterisk/trunk@399978 f38db490-d61c-443f-a65b-d21fe96a405b