Release v51.7 for Shelly dimmer and Shelly dimmer 2

This version removes support for no-neutral setups in favor of fixing flickering some users have experienced.

Release v51.6 for Shelly dimmer and Shelly dimmer 2

This version adds support for using the Shelly dimmer 2 in a 'no-neutral' setup.
Also adds a new low_brightness_threshold parameter (Tasmota command: ShdWarmupBrightness) which improves dimming at low brightnesses. More information can be found in pull request #23.

Release v51.5 for Shelly dimmer and Shelly dimmer 2

This version fixes an issue where some uses saw a high frequency 'flickering' of the light.
This release is designed to work with Tasmota version 9.1.0.2+.