ErikZalm/Marlin — pull request #851 by DanNixon (2014-03-21 20:47:00+00:00)
Title: Implemented M112

Checking for M112 after each new command enters the command buffer.
Call ```get_command()``` from ```process_inactivity()``` to preempt moves and heater.
Response is not instant, however is much faster than pausing print.