Updates to edge/dev. Line buffer increased/planner buffer decreased. Line overflow feedback.

- Increased g-code parser line buffer to 70 characters (from 50) to
prevent some long arc commands from getting truncated.

- Decreased planner buffer from 18 to 17 blocks to free up memory for
line buffer.

- Added a line buffer overflow feedback error (Thanks @BHSPitMonkey!)

report.h

@@ -36,6 +36,7 @@
 #define STATUS_IDLE_ERROR 11
 #define STATUS_ALARM_LOCK 12
 #define STATUS_SOFT_LIMIT_ERROR 13
+#define STATUS_OVERFLOW 14
 
 // Define Grbl alarm codes. Less than zero to distinguish alarm error from status error.
 #define ALARM_LIMIT_ERROR -1