Fix pokedex dump -l argument error - PR Changes

All changes requested in PR 17f36243bc

 ### pokedex/main.py -
 #### create_parser() -
- Change to langs argument reverting the help message to the original
one but changing the default to 'all'.
 #### command_dump() -
- Add check for 'all' langs code instead of in the load.py file.
- Add/fix comments.
---
 ### pokedex/db/load.py -
 #### dump() -
- Remove unneeded check for 'all' langs code since not it is checked in
the main.py file.
- Reword comment of what happens when the 'none' code is passed.

pokedex/db/load.py

@@ -431,11 +431,11 @@ def dump(session, tables=[], directory=None, verbose=False, langs=None):
         # if specified, or for official languages by default.
         # For non-translation tables, dump all rows.
         if 'local_language_id' in columns:
-            # If no lang arguments were passed or the 'all' argument was passed
-            if langs is None or langs == ['all']:
+            if langs is None:
                 def include_row(row):
                     return languages[row.local_language_id].official
-            # If the none argument is passed then nothing should be changed from the csv files
+            # If the none code is passed, then all the csv files with the local_language_id
+            # column are not updated. In other words they are left blank.
             elif langs == ['none']:
                 return False
             elif any(col.info.get('official') for col in table.columns):