Use a subclass of AdminServlet to allow disabling the metrics servlets

config properties:

rundeck.web.metrics.servlets.[name].enabled=true/false

names are:

* metrics
* threads
* ping
* healthcheck
Replace use of storage/keys api in GUI with wrapped action
Allow base layout to render if outside of sitemesh page context
Require all api actions come via /api urls
CLI tools need to use POST for api calls

* job run
* script/command/scriptfile run
Update API test code to use POST for job/command run/abort
rd-queue kill uses POST
Remove report create API endpoint mapping
Cleanup
Web GUI login disallows /api access