Adds lib directory. Is_Valid does not raise Request_Error.
Adds obj directory. Optimizes Is_Valid function in Ether.Requests
* Changes Responses.Send's Content parameter from String to
  Unicode.CES.Utf8.Utf8_String which is a subtype of String.
* Responses.Send raises an exception if the given status code
  is 1xx, 204 or 304 and the content argument is not empty.
Adds link to scgi protocol description to the readme file