FS-11785 [mod_conference] Fix dead assignments.  Removed auto-record-canvas-id param which never did anything.

                          fix dead assignments in conference_cdr

               null attribute in esl_buffer_read
	       null attribute in esl_event_base_add_header
	       null attribute in esl_recv_event

FS-11785 [mod_commands] scan-build thinks NULL parameter is being passed to function.  Shouldn't actually happen.

FS-11785 [mod_av] fix a couple dead assignments and inconsistent assumption that mm pointer could be NULL

FS-11784 [mod_sofia] quiet the codec negotiation error log.  It's something that is not necessarily a FS issue.

FS-11713: [core] fix a calls b with video, b answers with audio and then turns on video (A will have to unpause video too)

FS-11728 [core] add switch_ivr_play_and_collect_input().  This function plays a prompt while looking for DTMF or speech and returns whatever was heard.

(enable with sofia profile param rfc-7989=true)

FS-11557 [mod_sofia, mod_conference, core] Add support for re-INVITE when setting Session-ID in conference after call has been answered.

FS-11557 [mod_conference] Missed a spot where APP_SESSION_ID needed to be set.

FS-11557: set session id for outbound (initial requests)

FS-11557: [mod_sofia] rename vars and functions "session id" -> "session uuid" to reflect the real meaning for rfc7989.

FS-11557: fix bug - colliding chan var names (session_id)

FS-11557: check nil session uuid

FS-11557 : replace CS_NEW with CS_INIT for when originating calls, generate new uuid.

FS-11557: handle inbound (UAS mode, one leg)

FS-11557: generic param handling and filter via new sip profile option "rfc-7989-filter", eg:
<param name="rfc-7989-filter" value="logme, sec-agree, privacy" />

FS-11557: renamed chan vars (reflect meaning only for RFC7989)

FS-11557: fallback to RFC7329 - "old" Session-ID

FS-11557: distinguish between request and replies when we read the header
(to provide compatibility with old RFC7329 - section 11 of RFC7989)
FS-11557: change more vars/consts names

FS-11557: move compat flag on the channel.

FS-11557: add Session-ID header in REFER

FS-11557: needs extra condition on received initial request

FS-11557: handle NOTIFY

FS-11557: support answer() in dialplan - it was sending back a 200 OK with Session-ID invalid, eg: A=NIL;B=X

FS-11557: add Session-ID for NOTIFY (more cases)

FS-11557: handle reply to SIP INFO (add Session-ID header)

FS-11557: handle case of BYE after REFER, when the channel is destroyed already (save the uuid on sofia_private)

FS-11557: handle more SIP reply cases (eg: 202 Accepted , more negative replies)

FS-11557: handle ACK (UAS role)

FS-11557: added "rfc-7989-force-old" profile param - to enforce old rfc7329 for the UAC role. default off.
enabled with "<param name="rfc-7989-force-old" value="true" />".

FS-11557: fallback to rfc7329 fixes.

FS-11557: set flag CF_RFC7329_COMPAT on partner channel where needed

FS-11557: fix crash (mod_conference)