Add basic CLI and remove Rake helpers

##### Added basic CLI for Sanford 

This will eventually replace the rake helpers and will be the
primary way for managing Sanford server processes. This is to
better support upcoming features like "hot restarting" and also to
stop using rake in general.

##### Removed rake helpers

This removes the rake helpers from Sanford and stops using them
for the benchmark tasks. I replaced the benchmark tasks and use
the CLI instead. This is to remove our dependency and usage of
Rake, which the CLI replaces. I also changed the port number used
by the bench server/runner because it had chances to conflict with
the test suite (if the server was running it blew up the test
suite).