Removing MY_LED_BLINKING_FEATURE, as we now are
using MY_DEFAULT_LED_xx_PIN defines to enable
LED blinking feature.
updated Gateway sketches to not refer to
MY_LED_BLINKING_FEATURE any more
fixes#562
* Make smartSleep send heartbeat before sleeping
Sending the heartbeat (and waiting) after waking up would delay
processing inputs. For example, a switch could be back to the
open state before the wait is over.
* Fix typos in comments in smartSleep methods