- first go at adding i2c
- i2c working ok for spindle
- i2c disabled for cooling
- using led for status
- i2c latest
- merge i2c step1

Squashed commit of the following:

commit 1fd45791a52cda924683d88311c108908c51b598
Author: Sonny Jeon <chamnit@gmail.com>
Date:   Wed Feb 19 07:48:09 2014 -0700

	Minor updates to line number feature.

commit 9c95c1439f0fc2dde534d47ab1110062c44c42aa
Author: Sonny Jeon <chamnit@gmail.com>
Date:   Wed Feb 19 07:32:51 2014 -0700

	Merge pull request #356 from robgrz/dev

commit b332d6edbba7b147fba7be4779a68a44ad9c5df1
Author: Sonny Jeon <chamnit@gmail.com>
Date:   Wed Feb 19 07:21:40 2014 -0700

	Commenting updates. Minor bug fix with exit of soft limit event.

commit 2307563d8a097780507b2ec12b3fa1d6556f89ab
Author: Robert Grzesek <robert@robgrz.com>
Date:   Tue Feb 18 18:23:39 2014 -0800

	Merge commit 'cd71a90ce8a770e0030ed6c9bac805b89724e275' into dev

commit 3df61e0ec5f7cb0b4c09a847558ecf14a8697802
Author: Sonny Jeon <chamnit@gmail.com>
Date:   Sat Feb 15 13:13:46 2014 -0700

	Homing and feed hold bug fixes.

commit 50fbc6e2972acadbe5db944ddf33d12a8d94f4a0
Author: Sonny Jeon <chamnit@gmail.com>
Date:   Sun Feb 09 10:46:34 2014 -0700

	Refactoring and lots of bug fixes. Updated homing cycle.

commit cd71a90ce8a770e0030ed6c9bac805b89724e275
Author: Robert Grzesek <robert@robgrz.com>
Date:   Thu Feb 06 15:19:30 2014 -0800

	Made line number reporting optional via config.h

commit 6fdb35a7dad3e4ef027260aa30aef1fb0e55c554
Author: Robert Grzesek <robert@robgrz.com>
Date:   Thu Feb 06 15:10:27 2014 -0800

	Initial line number reporting
Merge branch 'dev' of https://github.com/grbl/grbl into dev

Conflicts:
	config.h
	coolant_control.c
	cpu_map.h
	limits.c
	main.c
	motion_control.c
	protocol.c
	report.c
	settings.h
	spindle_control.c
	stepper.c
	system.c

- add i2c code
- spindle/coolant control via i2c
Merge branch 'dev' of https://github.com/grbl/grbl.git into dev

Conflicts:
	config.h
	defaults.h
	gcode.c
	limits.c
	motion_control.c
	motion_control.h
	planner.c
	planner.h
	protocol.c
	report.c
	settings.h
	stepper.c
	system.c
	system.h
Merge branch 'dev' of https://github.com/grbl/grbl.git into dev
- update patches to current head
resolved Conflicts:
	coolant_control.c
	gcode.c
	settings.h
	spindle_control.c
- homing resets to coord zero
- tool length config
- tool length affects soft limits

Conflicts:
	gcode.c
	settings.h