Third time's a charm?  Sorry to flood you with closed pull requests.  Here is the tested version that matches the pull request on the groundcontrol software

Here is the latest version.  It includes code to save state of servos and reset them when the ESTOP condition is cleared.

This has been tested with the pull request for the groundcontrol software and both work together to implement this function cleanly.

Users will need to modify the USE_ESTOP to be 1 instead of 0 to enable this functionality so this firmware can be dropped on existing machines with no negative effects.

-Andrew