Implement some basic terminal commands

[kjlaw89]

Add the ability to query the status of monitored sites through the terminal. Something like:

com.github.kjlaw89.webwatcher -list - list all sites being monitored
com.github.kjlaw89.webwatcher -status - Get the status of all monitored sites
com.github.kjlaw89.webwatcher -status [id] - Get the status of a specific site
com.github.kjlaw89.webwatcher -add "[url]" - Add a new site to monitor
com.github.kjlaw89.webwatcher -remove [id] - Remove a specific site (deletes it)
com.github.kjlaw89.webwatcher -deactivate [id] - Disables a specific site
com.github.kjlaw89.webwatcher -reactivate [id] - Enables a specific site