Starting to refactor the normalizer to make sure that comments are also checked for indentation.

Using a linked list now for the indentation stack.

test/normalizer_issue_files/E11.py

@@ -4,14 +4,15 @@ if x > 2:
 if True:
     #: E111:5
      print
-    #: E116:6
+    #: E111:6
       # 
-    #: E116:2
+    #: E111:2
   # what
     # Comment is fine
 # Comment is also fine
 
 if False:
+    pass
 print
 print
 # TODO this shouldn't actually be a 111 but an IndentationError. Please
@@ -19,37 +20,40 @@ print
 #: E111:4
     print
 mimetype = 'application/x-directory'
-#: E116:5
+#: E111:5
      # 'httpd/unix-directory'
 create_date = False
 
 def start(self):
+    # foo
+    #: E111:8
+        # bar
     if True: # Hello
         self.master.start() # Comment
         # try:
-        #: E116:12
+        #: E111:12
             # self.master.start()
         # except MasterExit:
-        #: E116:12
+        #: E111:12
             # self.shutdown()
         # finally:
-        #: E116:12
+        #: E111:12
             # sys.exit()
     # Dedent to the first level
-    #: E116:6
+    #: E111:6
       # error
 # Dedent to the base level
-#: E116:2
+#: E111:2
   # Also wrongly indented.
 # Indent is correct.
 def start(self):  # Correct comment
     if True:
-        #: E115:0
+        #: E111:0
 #       try:
-        #: E115:0
+        #: E111:0
 #           self.master.start()
-        #: E115:0
+        #: E111:0
 #       except MasterExit:
-        #: E115:0
+        #: E111:0
 #           self.shutdown()
         self.master.start() # comment