bridge: Make "bridge destroy" only available in developer mode and add "all" to "bridge kick".

The "bridge destroy" CLI command is invasive to bridges and can leave them in an unexpected
state for the users of them. Since this command may be useful for developers it is now
only available when developer mode is available. To take its place "all" has been added
as a valid option to the "bridge kick" CLI command. It will kick all of the channels
in the bridge out.

ASTERISK-23987
Reported by: Matt Jordan

Review: https://reviewboard.asterisk.org/r/3840/
........

Merged revisions 419536 from http://svn.asterisk.org/svn/asterisk/branches/12


git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@419537 65c4cc65-6c06-0410-ace0-fbb531ad65f3