Convert /systemconfig/status to Restlet.

Convert the /systemconfig/status API calls from the previous standard
servlet into a Restlet enabled architecture.

The main motivation for moving to Restlet is to take advantage of the
better url handling that I had to do manually previously.

Note that the relative URLs in systemconfig.js were changed to include
/webapps/ubc-copyright-alerts-BBLEARN/systemconfig/ because of a Restlet
bug where urls of the form:
	/webapps/ubc-copyright-alerts-BBLEARN/systemconfig//status
wouldn't be recognized due to the double / before status. Regular
servlets collapse // down to one / but Restlet doesn't. This is a known
bug but unfortunately haven't been fixed (seems to be little interest in
fixing it).

The new SchedulerManager is a singleton class that creates and manages
all the Quartz scheduler associated machinery. It just needs to be
initialized and stopped by another servlet on startup for the scheduling
of index jobs to work.
Convert /systemconfig/metadata to Restlet.

Same as previous commit, slowly moving all the API calls to Restlet.

Also found out I broke loading the schedule configuration due to not
loading the configuration file beforehand. Should be fixed now.
Convert /systemconfig/host to Restlet.

Same as the previous 2 commits, was a pretty straightforward conversion,
so no problems.
Convert /systemconfig/schedule to Restlet.

This is the last of the system config API to be converted to Restlet.
With this one converted, the old SystemConfigAPI servlet is no longer
needed. It has been converted into the SchedulerStarter servlet, whose
purpose is to run application initialization code, which at this point
consists of starting the scheduler and storing the host into the
database.