JmxUtils finally broken down

Scheduling classes are mostly isolated, started to work on breaking cyclic dependencies (but not finished yet). Sofar the refactoring is stable, but I'm going to start to move everything around, so better already commit this intermediate state.
All package cycles are now broken !

Moved a LOT of things around but very few code changes. Some of the classes were moved for purely technical reasons (break cycles) and it might make sense to rearrange them a bit more based on semantic reasons as well.

Maven enforcer rule added to ensure no cycles are created in the future.
Merge pull request #179 from jmxtrans/remove-package-cycles

Remove package cycles