Refresh icons for UI5 and UI7

[watou]

Have separate JSON files for UI5 vs. UI7 installations, so the Ecobee icons appear on UI7 as they do on UI5. Update the main thermostat icon to look like an ecobee3. Allow it to change on ModeState changes.

I don't expect to be trying to track changes in UI7's compatibility with thermostat plugins with updates to the plugin, but I hope my efforts leave it in a usable state on UI7.