[pentair] Improvements to binding

[jsjames]

Contribution with several key enhancements/improvements to the binding:

Added automotic discovery of devices
EasyTouch thing has been renamed to a more generic Controller
Controller makes liberal use of channel groups to better organize channels
Added support for reading and writing Controller schedules
Added support for synchronizing the controller time
Added support for direct control of Intelliflo pumps
Added support for IntelliBrite color selection
Added support for UOM for temperature and pump power.
Improved robustness of communication on RS485 bus
Move serial implementation to openhab-transport-serial from gnu.io