Initialize configuration and web application.

def init():
    """Initialize configuration and web application."""
    global app
    if app: return app
    conf.init(), db.init(conf.DbPath, conf.DbStatements)

    bottle.TEMPLATE_PATH.insert(0, conf.TemplatePath)
    app = bottle.default_app()
    bottle.BaseTemplate.defaults.update(get_url=app.get_url)
    return app