Cleanup swim wrapper

[baltzell]

In preparation for new swimming versions, do a little reorganization of org.jlab.clas.swimtools:

• Add ISwim interface of appropriate methods from Swim
• Add abstract ASwim for shared data and generic wrapping of some simple geometry calls
• Refactor Swim, now extends ASwim
  • Move stoppers to a new, separate class Stoppers
  • Move parameter setup to a new, separate class SwimPars
  • Move existing "new" adaptive methods, previously unused, to AdaptiveSwim
  • Remove some unused methods
• Add AdaptiveSwim with specific methods from Swim
• General cleanup

TODO: remove stuff from ISwim, add wrappers to ASwim.

Note, Swim's interface and functionality is unchanged.