Enable admin/sensors to work with non-default procedure description formats

This commit allows the /admin/sensor procedure editing page to work with sensors using procedure description formats other than standard O&M. The formats are queried using a new ProcedureFormatDAO, implemented by HibernateProcedureFormatDAO. A ServiceLoaderHelper object is also added to ease loading of implementations by the ServiceLoader, and a mapToJson Jstl function is also added.