Http basic and http digest authentication in go language. this library designed as a simple wrapper for http.requesthandler functions. features:
* http basic and http digest authentication.
* htpasswd and htdigest formatted files.
* automatic reloading of password files.
* pluggable interface for user/password storage.
* md5 and sha1 for basic authentication password storage.
* configurable digest nonce cache size with expiration.
* wrapper for legacy http handlers (http.handlerfunc interface)