This patch reworks the stats object dict and includes more data.
Also includes aprsis last update timestamp (from last recieved message).
This is used to help determine if the aprsis server connection is still
alive and well.
This patch adds the healthcheck app that uses the flask stats url
to fetch the internal stats of a running aprsd server. If the server is
up the stats will return and be checked for 'healthy' status.
IF the url fails to return, healthcheck will exit with -1. You can use
this script to restart aprsd if healthcheck exits with -1 status.
There is a check against the email thread. The email thread updates a
deadman's timer every 5 seconds. If that time gets older than 5
minutes, then healthcheck will say that's a failure and exit with -1.
You can call healthcheck and restart aprsd if it fails (exit -1)
