MXS-1220: Add simple functionality to resources

The resources now properly process parts of the uri. This allows, for
example, certain sessions to be inspected. The current functionality is
only intended for testing and provides no useful functionality.

The actions taken by the resource manager are not done via the
inter-thread messaging system. When the implementation of the messages and
the JSON representation of the resources is done, the REST API resource
can actually be used.

server/core/session.cc

@@ -993,4 +993,4 @@ void session_clear_stmt(MXS_SESSION *session)
 uint32_t session_get_next_id()
 {
     return atomic_add_uint32(&next_session_id, 1);
-}
+}