review functionality added in Asterisk 14.1.0 - Asterisk 15.0

[chadxz]

Think about these changes and see if there is anything that should be added to the library to improve support for them.

Asterisk 14.3.0

ARI
------------------
 * The 'ari set debug' command has been enhanced to accept 'all' as an
   application name.  This allows dumping of all apps even if an app
   hasn't registered yet.

 * 'ari set debug' now displays requests and responses as well as events.

Asterisk 14.2.0

ARI
------------------
 * The bridges resource now exposes two new operations:
   - POST /bridges/{bridgeId}/videoSource/{channelId}: Set a video source in a
     multi-party mixing bridge
   - DELETE /bridges/{bridgeId}/videoSource: Remove the set video source,
     reverting to talk detection for the video source

 * The bridge model in any returned response or event now contains the following
   optional fields:
   - video_mode: the video source mode for the bridge. Can be one of 'none',
     'talker', or 'single'.
   - video_source_id: the unique ID of the channel that is the video source
     in this bridge, if one exists.

 * A new event, BridgeVideoSourceChanged, has been added for bridges.
   Applications subscribed to a bridge will receive this event when the source
   of video changes in a mixing bridge.

 * The ARI major version has been bumped. There are not any known breaking changes
   in ARI. The major version has been bumped because otherwise we can end up with
   overlapping version numbers between different Asterisk versions. Now each major
   version of Asterisk will bring with it a change in the major version of ARI.
   The ARI version in Asterisk 14 is now 2.0.0.

res_ari
------------------
 * The configuration file ari.conf now supports a channelvars option, which
   specifies a list of channel variables to include in each channel-oriented
   ARI event.

Asterisk 14.1.0

res_ari
------------------
 * ARI events will all now include a new field in the root of the JSON message,
   'asterisk_id'.  This will be the unique ID for the Asterisk system
   transmitting the event.  The value can be overridden using the 'entityid'
   setting in asterisk.conf.

[chadxz]

I opened #113 to request adding support for some of this, and the rest looks like it doesn't affect the library