New modules mimetools and rfc822.
Minor, minor changes to commands.py and sndhdr.py.
diff --git a/Lib/commands.py b/Lib/commands.py
index 5e4a9cf..d8c6e65 100644
--- a/Lib/commands.py
+++ b/Lib/commands.py
@@ -49,7 +49,7 @@
 		return ' \'' + x + '\''
 	s = ' "'
 	for c in x:
-		if c in '\\$"':
+		if c in '\\$"`':
 			s = s + '\\'
 		s = s + c
 	s = s + '"'