Updating steam.py streaming script

- Added push message capability to the stream.py streaming script. It
prints out as a `Debug:` string in the output.

doc/script/stream.py

@@ -11,6 +11,7 @@
 buffer layer to prevent buffer starvation.
 
 CHANGELOG:
+- 20161212: Added push message feedback for simple streaming
 - 20140714: Updated baud rate to 115200. Added a settings
  write mode via simple streaming method. MIT-licensed.
 
@@ -20,7 +21,7 @@
 ---------------------
 The MIT License (MIT)
 
-Copyright (c) 2012-2014 Sungeun K. Jeon
+Copyright (c) 2012-2016 Sungeun K. Jeon
 
 Permission is hereby granted, free of charge, to any person obtaining a copy
 of this software and associated documentation files (the "Software"), to deal
@@ -98,8 +99,13 @@
  l_block = line.strip() # Strip all EOL characters for consistency
  if verbose: print 'SND: ' + str(l_count) + ':' + l_block,
  s.write(l_block + '\n') # Send g-code block to grbl
- grbl_out = s.readline().strip() # Wait for grbl response with carriage return
- if verbose: print 'REC:',grbl_out
+ while 1:
+ grbl_out = s.readline().strip() # Wait for grbl response with carriage return
+ if grbl_out.find('ok') < 0 and grbl_out.find('error') < 0 :
+ print "\n Debug: ",grbl_out,
+ else : 
+ if verbose: print 'REC:',grbl_out
+ break
 else: 
  # Send g-code program via a more agressive streaming protocol that forces characters into
  # Grbl's serial read buffer to ensure Grbl has immediate access to the next g-code command
@@ -135,4 +141,4 @@
 
 # Close file and serial port
 f.close()
-s.close()
+s.close()