Add a few docstrings and update readme to-do list.

README.md

@@ -50,6 +50,7 @@ If you are interested in helping, please raise an issue before making any pull r
 - Make the FFmpeg path configurable. Some kind of global config? Or part of the database config file? It's not like every photodb needs a separate one.
 - Improve the appearance of album page. Too many section headers and the "Create album" interface should allow giving a title immediately.
 - When users have '%' or '#', etc. in their username, it is difficult to access their /user/ URL. I would prefer to fix it without simply blacklisting those characters.
+- Currently, the Jinja templates are having a tangling influence on the backend objects, because Jinja cannot import my other modules like bytestring, but it can access the methods of the objects I pass into the template. As a result, the objects have excess helper methods. Consider making them into Jinja filters instead. Which is also kind of ugly but will move that pollution out of the backend at least.
 
 ### To do list: User permissions
 Here are some thoughts about the kinds of features that need to exist within the permission system. I don't know how I'll actually manage it just yet. Possibly a `permissions` table in the database with `user_id | permission` where `permission` is some reliably-formatted string.

etiquette/exceptions.py

@@ -12,6 +12,13 @@ def pascal_to_loudsnakes(text):
 
 class ErrorTypeAdder(type):
     '''
+    During definition, the Exception class will automatically receive a class
+    attribute called `error_type` which is just the class's name as a string
+    in the loudsnake casing style. NoSuchPhoto -> NO_SUCH_PHOTO.
+
+    This is used for serialization of the exception object and should
+    basically act as a status code when displaying the error to the user.
+
     Thanks Unutbu
     http://stackoverflow.com/a/18126678
     '''
@@ -20,6 +27,12 @@ class ErrorTypeAdder(type):
         cls.error_type = pascal_to_loudsnakes(name)
 
 class EtiquetteException(Exception, metaclass=ErrorTypeAdder):
+    '''
+    Base type for all of the Etiquette exceptions.
+    Subtypes should have a class attribute `error_message`. The error message
+    may contain {format} strings which will be formatted using the
+    Exception's constructor arguments.
+    '''
     error_message = ''
     def __init__(self, *args, **kwargs):
         self.given_args = args

etiquette/objects.py

@@ -325,6 +325,7 @@ class Album(ObjectBase, GroupableMixin):
             photos = self.walk_photos()
         else:
             photos = self.photos()
+
         for photo in photos:
             photo.add_tag(tag, commit=False)
 
@@ -499,6 +500,9 @@ class Bookmark(ObjectBase):
     @decorators.required_feature('bookmark.edit')
     @decorators.transaction
     def edit(self, title=None, url=None, *, commit=True):
+        '''
+        Change the title or URL. Leave None to keep current.
+        '''
         if title is None and url is None:
             return