Anubis / Xlib

Changing etag from sha1 to MD5

…string.anubis function.

Minor other changes.

…itial_state() function.

Allowing to define the states folder

- headers are now read using a buffer and no more bytes per bytes
- adding headers 'Date' and 'Last-Modified' allowing to improve efficiency of browser cache
- adding header 'Server' just for decoration.

…h the displayed label.