Renamed, where appropriate, the configuration options for chan/res_pjsip to use
snake case (compound words separated by an underscore). For example, faxdetect
will become fax_detect, recordofffeature will become record_off_feature, etc...
Review: https://reviewboard.asterisk.org/r/3002/
git-svn-id: https://origsvn.digium.com/svn/asterisk/branches/12@403022 65c4cc65-6c06-0410-ace0-fbb531ad65f3