givenergy-local minimal rebase on givtcp dev3 modbus

This release is a " it just a bout works" effort. It relies on replacing the dewit 10.1 modbus Python moduel with a github reidjr/ version, which is a cut and paste of the modbus code from britkat/GivTCP.
Modbus changes support newest pre-release firmwares. Gen2 911 tested.
911 introduces a true Pause for the battery, which can be timed. On Gen1 pause is available without the timer.
Suppport for 10 charge discharge slots are supported by 911, but not yet by the GivTCP modbus modules.

Working with pip install -e

Fully replace modbus with givetcp version, update to work with crc changes. AIO stubbed out.