Fixed shared build info code.

- The build info options of “two switches on an axis” and “homing init
lock” shared the same letter ‘L’. The former is now ’T’.

doc/csv/build_option_codes_en_US.csv

@@ -6,7 +6,7 @@
 "P","Parking motion","Enabled"
 "Z","Homing force origin","Enabled"
 "H","Homing single axis commands","Enabled"
-"L","Two limit switches on axis","Enabled"
+"T","Two limit switches on axis","Enabled"
 "A","Allow feed rate overrides in probe cycles","Enabled"
 "D","Use spindle direction as enable pin","Enabled"
 "0","Spindle enable off when speed is zero","Enabled"

doc/log/commit_log_v1.1.txt

@@ -1,3 +1,15 @@
+----------------
+Date: 2017-02-23
+Author: Sonny Jeon
+Subject: Restrict coincident target updates to M3 constant laser only.
+
+- Restrict M3 forced updates when there is a motion block with a
+coincident target. Force syncing of the spindle state can lead to some
+pauses during a job that has coincident targets. That’s not
+particularly desirable. This ensures M4 dynamic mode is not effected by
+this force-sync.
+
+
 ----------------
 Date: 2017-02-23
 Author: Sonny Jeon

doc/markdown/interface.md

@@ -426,7 +426,7 @@ Feedback messages provide non-critical information on what Grbl is doing, what i
 | **`P`** | Parking motion enabled |
 | **`Z`** | Homing force origin enabled |
 | **`H`** | Homing single axis enabled |
-| **`L`** | Two limit switches on axis enabled |
+| **`T`** | Two limit switches on axis enabled |
 | **`D`** | Spindle direction pin used as enable pin |
 | **`0`** | Spindle enable off when speed is zero enabled |
 | **`S`** | Software limit pin debouncing enabled |