Allow the mapping from monitor to JMX ObjectName to be configurable via ...

...the ObjectNameMapper interface. Added an ordered based mapper which maps known properties in a given order which is useful for tools such as VisualVM who use the ordering to build the viewable mbean hierarchy, also this provides the option of not appending the additional tags but this should be used with care to prevent name collisions. Allow the "type" tag to be configurable via the servo.datasourcetype.key system property as tools such as VisualVM always order "type" at the top of the hierarchy. Replaced hard references then to "type". Resolves #155.