More code that somehow got left out of sig_analog

* confirmanswer option now respected
* check and set waiting for dialtone timer
* unneeded needcallerid flag removed from analog_subchannel
* ss_astchan does not need to be a void pointer
* swap_channels callback updated to trunk
* analog_hangup now resets channel to default law


git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@212287 65c4cc65-6c06-0410-ace0-fbb531ad65f3