Add a notion of extension directories.

bambam.py

@@ -163,6 +163,7 @@ def load_items(cls, lst, blacklist, load_function, failure_message):
 
     def __init__(self):
         self.data_dirs = []
+        self.extensions_dirs = []
 
         self.background_color = None
         self.background = None
@@ -400,6 +401,12 @@ def _add_base_dir(self, base_dir):
             print(_('Using data directory %s') % data_subdir)
             self.data_dirs.append(data_subdir)
 
+        extensions_subdir = os.path.join(base_dir, 'extensions')
+        if os.path.isdir(extensions_subdir):
+            # TRANSLATORS: An extension directory is a directory which contains extensions.
+            print(_('Using extension directory %s') % extensions_subdir)
+            self.extensions_dirs.append(extensions_subdir)
+
     def run(self):
         """
         Main application entry point.