models: move all models under litle/models

Signed-off-by: Pierre-Alexandre Meyer <pierre@ning.com>
litle: move gateway under litle/litle

Signed-off-by: Pierre-Alexandre Meyer <pierre@ning.com>
config: move config to litle/config/properties

Signed-off-by: Pierre-Alexandre Meyer <pierre@ning.com>
sinatra: add a couple of useful endpoints

Signed-off-by: Pierre-Alexandre Meyer <pierre@ning.com>