Confbridge: Add references for kick all option

After the ability to kick all attendees from a conference was added, a
rework removed the comment about that feature from the CLI
documentation. This adds that documentation and adds "all" to the
participant tab completion list for the confbridge kick command.

(closes issue ASTERISK-23282)
Reported by: Dorian Logan


git-svn-id: http://svn.asterisk.org/svn/asterisk/branches/12@412728 f38db490-d61c-443f-a65b-d21fe96a405b
Confbridge: Fix ConfbridgeKick AMI documentation

This adds documentation for the "all" channel option for the
ConfbridgeKick AMI action and adjusts AMI responses accordingly.

(issue ASTERISK-23282)
Reported by: Dorian Logan


git-svn-id: http://svn.asterisk.org/svn/asterisk/branches/12@412730 f38db490-d61c-443f-a65b-d21fe96a405b