Added new branch, to be used with 433MHz-driven heaters

[jjouifi]

Hello,

I've been using the SVT plugin with mods for quite some time now, and wanted to share them with you.
Basically, I'm using it to control 433MHz switches connected to the pilot wire. Two issues that my edits solve:

• Inverts the ON/OFF order (Simple 433MHz switch on pilot wire gives inverted order, and I don't want an extra layer of dummy switch + inversion mechanism)
• Sends the switching orders even if the state of the switch hasn't changed. This is to prevent locking situations when one order was missed, which happens sometimes with 433MHz. As a consequence, the heater remains stuck ON or OFF.

Hope it will be useful. Let me know if this is unclear.
Cheers,
JJ