chan_sip: complete upgrade to ao2

This change upgrades sip_registry and sip_subscription_mwi to astobj2.

ASTERISK-24067 #close
Reported by: Corey Farrell
Review: https://reviewboard.asterisk.org/r/3759/


git-svn-id: http://svn.asterisk.org/svn/asterisk/trunk@419438 f38db490-d61c-443f-a65b-d21fe96a405b
Deprecate astobj.h

This flags astobj.h as deprecated, warns people to use astobj2.h instead.
Only netsock.c (also deprecated) still uses astobj.h.

ASTERISK-24069 #close
Reported by: Corey Farrell
Review: https://reviewboard.asterisk.org/r/3818/


git-svn-id: http://svn.asterisk.org/svn/asterisk/trunk@419439 f38db490-d61c-443f-a65b-d21fe96a405b
Blocked revisions 419442

These change was applied to trunk in r419438

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chan_sip: sip_subscribe_mwi_destroy should not call sip_destroy

sip_subscribe_mwi_destroy calls sip_destroy on the reference counted
mwi->call.  This results in the fields of mwi->call being freed, but
mwi->call itself it leaked.  If other code is still using mwi->call
it can cause problems.  This change uses dialog_unref instead, to
balance the ref provided by sip_alloc().

ASTERISK-24087 #close
Reported by: Corey Farrell
Review: https://reviewboard.asterisk.org/r/3834/
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Merged revisions 419440 from http://svn.asterisk.org/svn/asterisk/branches/1.8
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Merged revisions 419441 from http://svn.asterisk.org/svn/asterisk/branches/11


git-svn-id: http://svn.asterisk.org/svn/asterisk/trunk@419443 f38db490-d61c-443f-a65b-d21fe96a405b