Allow for "natural" usage of normal FCGI structs when logical, yet

still correctly handle cases where we need to ship those structs
over the wire, by transforming them from FCGI structs to
unsigned char arrays. Place the logic of mapping that
struct to the arrays in distinct functions, isolating
them. 


git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/branches/fcgi-proxy-dev@367300 13f79535-47bb-0310-9956-ffa450edef68