This change adds a "watchdog notifier" utility which tracks the
health of request handlers and notifies an external systemd
watchdog if everything looks good. This allows us to cause a
termination if any request handlers get hung.
This includes adding facilities to handle termination signals
and err handling. Some modifications have been made to the file
input to accomodate the concurrency requirements. The slate
read mechanism is still fairly rudimentary and can only read
from a hardcoded file, but at this stage is for prototyping
purposes.
This change removes usage of netsender to provide remote
configuration of the service and replaces with a basic control
REST API with PUT and DELETE methods. PUT requests add or update
a broadcast, and DELETE removes a broadcast. In addition to these
changes, some modification of the NOOP lexer has been performed
including tuning of the controller.