Simplify stream handling.
Ignore CD added login config in auth ext, no need for CD auth method add.
Check if auth already in basic.
Refactor StaticServlet so we can add static-files headers and expiration handling
StaticServlet now sends http-headers as defined in static-files in appengine-web.xml
StaticServlet now honors <public-root> tag in appengine-web.xml
StaticServlet now adds caching-related headers to response