LISTEN / NOTIFY support
Use ExUnit filter for notification payload support checking
Remove Process.alive? check before sending a message
Monitors the process that has sent a LISTEN command, so we know when it has died.
Use per-channel monitoring instead of per-process monitoring
Cleaned up some code.
More clean-up; avoid unnecessary LISTEN / UNLISTEN queries.
Merge pull request #29 from keichan34/listen-notify

LISTEN / NOTIFY support