Dial API: Add a dial option to indicate the dialed channel will replace dialer

Dial API: Add a dial option to indicate the dialed channel will replace dialer

Adds an option to the dial API that marks an outgoing dial as replacing the dialing channel for the purpose of propagating accountcode. When it is used, AST_CHANNEL_REQUESTOR_REPLACEMENT is used instead of AST_CHANNEL_REQUESTOR_BRIDGE_PEER when setting accountcodes on the involved channels with ast_channel_req_accountcodes.

Review: https://reviewboard.asterisk.org/r/3968/

git-svn-id: https://origsvn.digium.com/svn/asterisk/branches/13@422684 65c4cc65-6c06-0410-ace0-fbb531ad65f3