Support for MIHO003 OpenSensor tested and working

Added MIHO033 OpenSensor to Devices.py

Documented messages from 3 new devices

Spec'ed out work required to add the new devices

Now runs on Raspberry Pi 3 also

working notes file device_classes_branch.txt moved over to an issue

Reviewed TODO list from the device_classes branch ...

The remaining items will be moved to an issue for later mop up

Removed sample programs and moved to issues in the issue log ...

These are not ready to be released yet and are at early ideas stage.

Updated README.md to bring in line with latest release

Merge pull request #61 from whaleygeek/device_classes ...

Device classes

New tests documented. ...

All tests done and pass

Tested and tweaked for Python 3 support

Tested demos on real hardware. Works fine. ...

Observation: handling of incoming messages does not check registry,
it only checks the router, so if you don't have a device object
bound to it, it will be seen as unknown. Needs fixing, but not a high
priority.

Tested setup_tool.py on real hardware - works OK ...

Some tweaks required but now works fine

All test cases now run fine. ...

There is no capture/compare at the moment, so verification is manual

All testers except Registry_test now running all tests

Rationalised all comment styles. ...

The double hash (##) is reserved for commented out lines of code.
The single hash (#) is reserved for normal comments.

Moved setup code from global scope of Registry to energenie.init() ...

This makes it possible to use the registry in test cases

auto variable create example added. ...

Tested in simulation, seems to work, but need to re-test on hardware

Energy monitor example written. ...

Not tested yet, as need to test with real devices

Standalone discovery example written. ...

Not able to test until real devices added

Improved registry listing by using iterator

Iterator added to registry

Clarified control_any_noreg.py by adding a MIHO005 example

Renamed a lot of the control_ demos, due to device agnostic behaviour

Removed control_both.py, as control_any.py will do any sockets now

control_mihome.py recoded to use remembered registry

control_legacy.py simplified, assuming learning done by setup_tool.py

setup_tool tested in simulation and works OK

setup_tool finished, ready for testing