BZ 1068816 - More remote methods for managing agent and server plugins, metrics

Exposing mostly methods already available as part of the Local interface.

Not sure if the List<Integer> methods should be exposed, as it is a hassle to use via JavaScript,
but it is possible to use these methods anyway.
Merge pull request #44 from genman/genman/moreremote

BZ 1068816 - More remote methods for managing agent and server plugins, metrics