Added settings for initial map center and zoom, and leaflet plugins
Fixed hardcoded static URL
Improved handling of LEAFLET_CONFIG['PLUGINS']; Documentation added for PLUGINS, DEFAULT_CENTER, DEFAULT_ZOOM
Fixed wrong tag for outputting plugins' CSS
Added new line at the end of __init__
Removed old test code
Fixes Internet Explorer 7 - addEventListener does not work on IE
Merge pull request #16 from sentido/feature-settings

Feature: Settings for Leaflet plugins, default map center and zoom level.