alter implementation of renegotiate codec on hold feature to still take other sdp elements into consideration

FS-3127 --comment-only can you try this patch first to see if it fixes it without any changes to mod_cc

FS-640 --comment-only can you see if this patch helps, I think it should really be fixed in sofia but this shold keep it at bay

Using ftdm_log_chan() in ftdm_analog_configure_span() is a bad idea,
since the span won't have any channels assigned.

This bug powered by declaring all variables at the top of the function,
even if they are used in an if branch at the end.

A C99'ish:

	if (callwaiting) {
		for (unsigned int i = 1; i <= span->span->chan_count; i++) {
			/* ... */
		}
	}

would have alerted the developer adding the log statement.
But since we can't have nice things (thanks MSVC for not supporting C99!)
</rant>
Signed-off-by: Stefan Knoblich <s.knoblich@axsentis.de>

This partially reverts commit 17d52112.

Some changes in that commit caused 393 files which are in the tree to
be mistakenly ignored.

FS-3121 this is less of a bug and more of a feature request but here you go, that's your quota for the month