Merge pull request #42 from betgear/door_fix

Fix for safety door, feed hold and cycle start bits.

Compiled bin files for all boards

Corrected G10 L20 P0 command (setZero)

Set coolant pins for all supported boards in cpu-map.h

Made board switchable in config.h

Corrected stepper invert mask for K40

Corrected K40 defaults

Error corrected in config.h (missing ")" on LIMIT_MASK)

Corrected release link in README.md

Corrected release link in README.md