Minor updates, improvements, and bug fixes.

- Allowed status_message function to be called by others. This is to
centralize all feedback into protocol.c.

- Fixed a bug where line number words 'N' were causing the parser to
error out.

- Allowed homing routine feed rates to move slower than the
MINIMUM_STEP_RATE parameter in config.h.

- Homing performs idle lock at the end of the routine.

- Stepper idle lock time will now not disable the steppers when the
value is set at 255. This is accomodate users who prefer to keep their
axes enabled at all times.

- Moved some defines around to where they need to be.

protocol.c

@@ -32,13 +32,11 @@
 #include "stepper.h"
 #include "planner.h"
 
-#define LINE_BUFFER_SIZE 50
-
 static char line[LINE_BUFFER_SIZE]; // Line to be executed. Zero-terminated.
 static uint8_t char_counter; // Last character counter in line variable.
 static uint8_t iscomment; // Comment/block delete flag for processor to ignore comment characters.
 
-static void status_message(int status_code) 
+void protocol_status_message(int8_t status_code) 
 {
   if (status_code == 0) {
     printPgmString(PSTR("ok\r\n"));
@@ -220,10 +218,10 @@ void protocol_process()
 
       if (char_counter > 0) {// Line is complete. Then execute!
         line[char_counter] = 0; // Terminate string
-        status_message(protocol_execute_line(line));
+        protocol_status_message(protocol_execute_line(line));
       } else { 
         // Empty or comment line. Skip block.
-        status_message(STATUS_OK); // Send status message for syncing purposes.
+        protocol_status_message(STATUS_OK); // Send status message for syncing purposes.
       }
       char_counter = 0; // Reset line buffer index
       iscomment = false; // Reset comment flag