cgi unbuffering. Includes various BUFF * routines for script/cgi that

suplement the FILE * routines.  BUFF's now nicely handle switching from
buffered reading to unbuffered reading.

Submitted by:	Dean Gaudet, Sameer Parekh, Roy Fielding
Reviewed by:	Brian Behlendorf


git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/branches/1.3.x@78762 13f79535-47bb-0310-9956-ffa450edef68