Major g-code parser overhaul. 100%* compliant. Other related updates.

- Completely overhauled the g-code parser. It’s now 100%* compliant. (*
may have some bugs). Being compliant, here are some of the major
differences.

- SMALLER and JUST AS FAST! A number of optimizations were found that
sped things up and allowed for the more thorough error-checking to be
installed without a speed hit. Trimmed a lot of ‘fat’ in the parser and
still was able to make it significantly smaller than it was.

- No default feed rate setting! Removed completely! This doesn’t exist
in the g-code standard. So, it now errors out whenever it’s undefined
for motions that require it (G1/2/3/38.2).

- Any g-code parser error expunges the ENTIRE block. This means all
information is lost and not passed on to the running state. Before some
of the states would remain, which could have led to some problems.

- If the g-code block passes all of the error-checks, the g-code state
is updated and all motions are executed according to the order of
execution.

- Changes in spindle speed, when already running, will update the
output pin accordingly. This fixes a bug, where it wouldn’t update the
speed.

- Update g-code parser error reporting. Errors now return detailed
information of what exact went wrong. The most common errors return a
short text description. For less common errors, the parser reports
‘Invalid gcode ID:20’, where 20 is a error ID. A list of error code IDs
and their descriptions will be documented for user reference elsewhere
to save flash space.

- Other notable changes:

- Added a print integer routine for uint8 variables. This saved
significant flash space by switching from a heavier universal print
integer routine.

- Saved some flash space with our own short hypotenuse calculation

- Some arc computation flash and memory optimizations.

defaults.h

@@ -42,7 +42,6 @@
   #define DEFAULT_Y_MAX_TRAVEL 200.0 // mm
   #define DEFAULT_Z_MAX_TRAVEL 200.0 // mm
   #define DEFAULT_STEP_PULSE_MICROSECONDS 10
-  #define DEFAULT_FEEDRATE 250.0 // mm/min
   #define DEFAULT_STEPPING_INVERT_MASK 0
   #define DEFAULT_DIRECTION_INVERT_MASK ((1<<Y_DIRECTION_BIT)|(1<<Z_DIRECTION_BIT))
   #define DEFAULT_STEPPER_IDLE_LOCK_TIME 25 // msec (0-254, 255 keeps steppers enabled)
@@ -82,7 +81,6 @@
   #define DEFAULT_Y_MAX_TRAVEL 125.0 // mm
   #define DEFAULT_Z_MAX_TRAVEL 170.0 // mm
   #define DEFAULT_STEP_PULSE_MICROSECONDS 10
-  #define DEFAULT_FEEDRATE 254.0 // mm/min (10 ipm)
   #define DEFAULT_STEPPING_INVERT_MASK 0
   #define DEFAULT_DIRECTION_INVERT_MASK ((1<<Y_DIRECTION_BIT)|(1<<Z_DIRECTION_BIT))  
   #define DEFAULT_STEPPER_IDLE_LOCK_TIME 25 // msec (0-254, 255 keeps steppers enabled)
@@ -125,7 +123,6 @@
   #define DEFAULT_Y_MAX_TRAVEL 200.0 // mm
   #define DEFAULT_Z_MAX_TRAVEL 200.0 // mm
   #define DEFAULT_STEP_PULSE_MICROSECONDS 10
-  #define DEFAULT_FEEDRATE 250.0
   #define DEFAULT_STEPPING_INVERT_MASK 0
   #define DEFAULT_DIRECTION_INVERT_MASK ((1<<Y_DIRECTION_BIT)|(1<<Z_DIRECTION_BIT))  
   #define DEFAULT_STEPPER_IDLE_LOCK_TIME 255 // msec (0-254, 255 keeps steppers enabled)
@@ -158,17 +155,16 @@
   #define DEFAULT_X_STEPS_PER_MM (MICROSTEPS_XY*STEP_REVS_XY/MM_PER_REV_XY)
   #define DEFAULT_Y_STEPS_PER_MM (MICROSTEPS_XY*STEP_REVS_XY/MM_PER_REV_XY)
   #define DEFAULT_Z_STEPS_PER_MM (MICROSTEPS_Z*STEP_REVS_Z/MM_PER_REV_Z)
-  #define DEFAULT_X_MAX_RATE 800.0 // mm/min
-  #define DEFAULT_Y_MAX_RATE 800.0 // mm/min
-  #define DEFAULT_Z_MAX_RATE 800.0 // mm/min
-  #define DEFAULT_X_ACCELERATION (15.0*60*60) // 15*60*60 mm/min^2 = 15 mm/sec^2
-  #define DEFAULT_Y_ACCELERATION (15.0*60*60) // 15*60*60 mm/min^2 = 15 mm/sec^2
-  #define DEFAULT_Z_ACCELERATION (15.0*60*60) // 15*60*60 mm/min^2 = 15 mm/sec^2
+  #define DEFAULT_X_MAX_RATE 500.0 // mm/min
+  #define DEFAULT_Y_MAX_RATE 500.0 // mm/min
+  #define DEFAULT_Z_MAX_RATE 500.0 // mm/min
+  #define DEFAULT_X_ACCELERATION (25.0*60*60) // 25*60*60 mm/min^2 = 25 mm/sec^2
+  #define DEFAULT_Y_ACCELERATION (25.0*60*60) // 25*60*60 mm/min^2 = 25 mm/sec^2
+  #define DEFAULT_Z_ACCELERATION (25.0*60*60) // 25*60*60 mm/min^2 = 25 mm/sec^2
   #define DEFAULT_X_MAX_TRAVEL 200.0 // mm
   #define DEFAULT_Y_MAX_TRAVEL 200.0 // mm
   #define DEFAULT_Z_MAX_TRAVEL 200.0 // mm
   #define DEFAULT_STEP_PULSE_MICROSECONDS 10
-  #define DEFAULT_FEEDRATE 250.0
   #define DEFAULT_STEPPING_INVERT_MASK 0
   #define DEFAULT_DIRECTION_INVERT_MASK ((1<<Y_DIRECTION_BIT)|(1<<Z_DIRECTION_BIT))
   #define DEFAULT_STEPPER_IDLE_LOCK_TIME 255 // msec (0-254, 255 keeps steppers enabled)
@@ -209,7 +205,6 @@
   #define DEFAULT_Y_MAX_TRAVEL 180.0 // mm
   #define DEFAULT_Z_MAX_TRAVEL 150.0 // mm
   #define DEFAULT_STEP_PULSE_MICROSECONDS 10
-  #define DEFAULT_FEEDRATE 1000.0 // mm/min
   #define DEFAULT_STEPPING_INVERT_MASK 0
   #define DEFAULT_DIRECTION_INVERT_MASK ((1<<Y_DIRECTION_BIT))  
   #define DEFAULT_STEPPER_IDLE_LOCK_TIME 25 // msec (0-254, 255 keeps steppers enabled)