New switchmodes TOGGLEMULTI, FOLLOWMULTI and FOLLOWMULTI_INV

[to-scho]

Description:

This may solve #7519 as enhancement

Related issue (if applicable): fixes #

Checklist:

• The pull request is done against the latest dev branch
• Only relevant files were touched
• Only one feature/fix was added per PR.
• The code change is tested and works on core 2.6.1
• The code change pass travis tests. Your PR cannot be merged unless tests pass
• I accept the CLA.

[jensuffhaus]

@to-scho @arendst

I have just upgraded my one Sonoff Mini to the latest development build and my testing so far shows the multi toggle feature is working, at least a double toggle. A triple toggle results in a double toggle mqtt message and then a local relay toggle.

A future enhancement may be to allow infinite toggles all with the 500ms gap and have the toggle count as the mqtt payload but for now the double toggle will suffice.

This is a great feature for light switch automation and will allow so much existing old hardware to be used as smart input.

Thanks @to-scho for the quick response.