add comments

fslgui/gui.py

@@ -14,6 +14,10 @@ import fslgui.tools as tools
 
 
 class BaseGui(object):
+    """
+    BaseGui is the parent class for all FSL GUIs.
+    Common functionality and attributes are implemented here.
+    """
     def __init__(self):
         # maybe add some other common funcionality here
         pass