Added better docstrings to subpackages and cleaned out some places which were unclear.

evennia/commands/__init__.py

@@ -1 +1,10 @@
 # -*- coding: utf-8 -*-
+"""
+This sub-package contains Evennia's command system. It handles
+everything related to parsing input from the player, building cmdsets
+and executing the code associated with a found command class.
+
+commands.default contains all the default "mux-like" commands of
+Evennia.
+
+"""