Critical M0/2/30 fix. Homing updates.

- Critical fix for M0 program pause. Due to its recent change, it would
cause Grbl to suspend but wouldn’t notify the user of why Grbl was not
doing anything. The state would show IDLE and a cycle start would
resume it. Grbl now enters a HOLD state to better indicate the state
change.

- Critical fix for M2 and M30 program end. As with M0, the state
previously would show IDLE while suspended. Grbl now does not suspend
upon program end and leaves job control to the GUI. Grbl simply reports
a `[Pgm End]` as a feedback message and resets certain g-code modes.

- M2/30 g-code reseting fix. Previously Grbl would soft-reset after an
M2/30, but this was not complaint to the (linuxcnc) g-code standard. It
simply resets [G1,G17,G90,G94,G40,G54,M5,M9,M48] and keeps all other
modes the same.

- M0/M2/M30 check-mode fix. It now does not suspend the machine during
check-mode.

- Minor bug fix related to commands similar to G90.1, but not G90.1,
not reporting an unsupported command.

- Homing cycle refactoring. To help reduce the chance of users
misunderstanding their limit switch wiring, Grbl only moves a short
distance for the locate cycles only. In addition, the homing cycle
pulls-off the limit switch by the pull-off distance to re-engage and
locate home. This should improve its accuracy.

- HOMING_FORCE_ORIGIN now sets the origin to the pull-off location,
rather than where the limit switch was triggered.

- Updated default junction deviation to 0.01mm. Recent tests showed
that this improves Grbl’s cornering behavior a bit.

- Added the ShapeOko3 defaults.

- Added new feedback message `[Pgm End]` for M2/30 notification.

- Limit pin reporting is now a $10 status report option. Requested by
OEMs to help simplify support troubleshooting.

doc/log/commit_log_v0.9i.txt

@@ -1,3 +1,29 @@
+----------------
+Date: 2015-03-29
+Author: Sonny Jeon
+Subject: Fix for limit pin reporting compile-option
+
+- The limit pin reporting wasn’t working correctly due to calling the
+wrong similarly-named function. Verified to be working now.
+
+
+----------------
+Date: 2015-03-29
+Author: Sonny Jeon
+Subject: Commit history, logo license, full-arc fix.
+
+- Commit history added to repo, as an easier way for people to see view
+the changes over time.
+
+- Grbl logo copyright license added. All rights reserved with regards
+to the Grbl logo.
+
+- G2/3 full circles would sometime not execute. The problem was due to
+numerical round-off of a trig calculation. Added a machine epsilon
+define to help detect and correct for this problem. Tested and should
+not effect general operation of arcs.
+
+
 ----------------
 Date: 2015-03-27
 Author: Sungeun Jeon