Update README.mdown

Fix: Updated makefiles to assume ejabberd lives in /usr/lib/ejabberd

Added MIT license

Feature: Added message_hook support

Feature: Added README

Feature: HTTP calls are now made asynchronously

Fix: Will now send offline hook when unset_presence_hook is called from an offline presence message, and there are no other resources

Fix: Corrected description to match functionality of module

Feature: Now supports events for user going online (first connection), and offline (no other connections)

Feature: Can now make HTTP Posts on calls of set_presence and unset_presence

Basic logging of presence hooks

Initial commit