Perform reverse search for all images in a directory (using e621.net/iqdb_queries & saucenao.com)
By default this service allows 150 searches per 24 hours per IP, you can raise this limit by providing API key in the config file. To get your personal API key you have to register an account on saucenao.com.
Added support for saucenao.com service
Final fix for #7