Stand Alone arduino GRBL controller

The project was developed in Arduino IDE 1.6.7! Other versions may have problems.

[Link to original project](http://www.cnc-club.ru/forum/viewtopic.php?f=41&t=10940)

P.S.: I fix reset in original firmware
....
pinMode(GRBL_RES_PIN, OUTPUT);
digitalWrite(GRBL_RES_PIN, HIGH);
delay(200);
digitalWrite(GRBL_RES_PIN, LOW);