Metacat

Add placeholder NotImplemented exceptions for getOperationsStatistics() and getCapabilities() in MNodeService.

Implement MNCore.ping() by testing for a successful database connection.

Minor housekeeping - tabs to spaces.

Implement update() in MNodeService. Handle both XML science metadata updates and data object updates. Keep system metadata up to date, and log the update event.

Make isScienceMetadata() protected for access from subclasses.

Add insertSystemMetadata() to D1NodeService, wrap the exception handling from calls to IdentifierManager.

Add updateSystemMetadata() to D1NodeService as a helper method to wrap the exception handling from calls to IdentifierManager.

At Ben's suggestion, add metacatUrl to D1NodeService and make it available to subclasses. Set the metacatUrl in the constructor using SystemUtil rather than all roll your own PropertyService calls. More concise. Also, log the delete event in MNodeService.delete().

add CNRestServlet and mappings for urls in the form:
/d1/cn/*
This extends existing code for CN-specific handling. MN handling will be analogous and is forthcoming

share the deserializer method with subclasses