Create serial-hcsr04-loop-smooth.ino

Serialreading for multiple HCSR-04
Using Paul Badger's digitalSmooth for noise removing
The sketch is made for 6 ultrasonic sensors pointed on one target person at their middle to make sure he or she does not move at all.
Interferencies are avoided by looping the triggers one after the other.
For now, it only does it for two of them, but that will change very soon