[base] TaggedPtr: new API for embedding tags into pointers.
[http] HttpMessageProcessor: make sure we can parse HTTP message responses with content-length explicitely set to 0.
[http] HttpClient: new client HTTP API to connect to HTTP servers.
some more bits on the HttpServer test
autogen.sh: default to llvm-3.1
[examples] tcp-echo-server: mute compiler warning
[tests] fixed compile issues
[http] HttpRequest: added helper method to easily send a static file to the client with all the features (Content-Type, ETag, client side caching, ranged requests, ...) and adapted the core staticfile() code to use it.
[plugins] director: added initial support for X-Sendfile. refs #68