Fix pokedex dump -l argument error - PR Changes

### pokedex/main.py -
 #### create_parser() -
- Change the default in the the help text for the `-l` argument in the
`pokedex dump` parser.

 #### command_dump() -
- Change the functionality of `pokedex dump -l none` to be the same as
entering `pokedex dump`.

---

 ### pokedex/db/load.py -
 #### dump() -
- Change the functionality of the dump command to work the way that the
help text says it should.
- Tables always dump official languages.
- If there were any `langs` passed, then the official languages plus the
specified `langs`  will be dumped from the tables that have a
'local_language_id' column.
- If `pokedex dump -l all` is passed then all the languages (official
and unofficial) will be dumped.
- If the table doesn't have a 'local_language_id' column, then all the
rows will be dumped.

pokedex/db/load.py

@@ -425,26 +425,34 @@ def dump(session, tables=[], directory=None, verbose=False, langs=None):
             writer = csv.writer(open(filename, 'wb'), lineterminator='\n')
             columns = [col.name.encode('utf8') for col in table.columns]
 
-        # For name tables, always dump rows for official languages, as well as
-        # for those in `langs` if specified.
-        # For other translation tables, only dump rows for languages in `langs`
-        # if specified, or for official languages by default.
-        # For non-translation tables, dump all rows.
+        # Tables always dump official languages.
+        # If there were any `langs` passed, then the official languages plus
+        # the specified `langs` will be dumped from the tables that have a 
+        # 'local_language_id' column.
+        # If the table doesn't have a 'local_language_id' column, then
+        # all the rows will be dumped.
         if 'local_language_id' in columns:
+            # If 'pokedex dump' OR 'pokedex dump -l none' were passed
+            # Only columns with official languages will be dumped.
             if langs is None:
                 def include_row(row):
                     return languages[row.local_language_id].official
-            # 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):
+            
+            # If 'pokedex dump -l all' was passed. All the columns will be 
+            # dumped, no matter if the language is official or not.
+            elif langs == ['all']:
+                def include_row(row):
+                    return True
+            
+            # If there is a/multiple language codes passed, then all the columns that are
+            # those languages OR are official languages will be dumped.
+            else:
                 def include_row(row):
                     return (languages[row.local_language_id].official or
                             languages[row.local_language_id].identifier in langs)
-            else:
-                def include_row(row):
-                    return languages[row.local_language_id].identifier in langs
+
+        # If there is no 'local_language_id' column in the table then all the rows
+        # are dumped.
         else:
             def include_row(row):
                 return True

pokedex/main.py

@@ -114,7 +114,7 @@ def create_parser():
         help="directory to place the dumped CSV files")
     cmd_dump.add_argument(
         '-l', '--langs', dest='langs', default=None,
-        help=u"comma-separated list of language codes to load, 'none', or 'all' (default: all)")
+        help=u"comma-separated list of language codes to load, 'none', or 'all' (default: none)")
     cmd_dump.add_argument(
         'tables', nargs='*',
         help="list of database tables to load (default: all)")
@@ -210,8 +210,9 @@ def command_dump(parser, args):
     if args.langs is not None:
         langs = [l.strip() for l in args.langs.split(',')]
         
-        # If the langs code is only 'all' then langs is None so that all the tables get dumped.
-        if len(langs) == 1 and langs[0] == 'all':
+        # If the `langs` code is 'none' then langs is None so only the official languages
+        # from the tables will be dumped. This is the same as if no `langs` were passed.
+        if len(langs) == 1 and langs[0] == 'none':
             langs = None
 
         # Check if either 'all' or 'none' codes are used along side other codes.