* no more backlight off mode for color lcd radios
disable backlight input controls in radio setup screen, when they are not used by the selected backlight mode
force backlight on to be at least the brightness of backlight off
* do not allow to set the display brightness below the configured off brightness, except when display mode is set to ON.
* Revert "do not allow to set the display brightness below the configured off brightness, except when display mode is set to ON."
This reverts commit e153a8dc658d53f5420c912e7543d6d0a9fe6ed9.
