Added Run Time, Pause State (runt time will continue),
*  Added pause menu, tool-bar button, icons and pause state.
*  Added Grbl DRO hack setting, if this is enabled and Grbl is the
   current device, the output GCODE will be used to update machine
   status; since Grbl does't have a verbose mode, and I seen issues
   if one  repeatedly queries Grbl for status while executing a program.
*  Enable commented-out code for run time status (elapsed time), also
   added the timer to display the data every 1000ms (1s).
*  Fixed state transitions to/from ABORT state.