HTTP/1.1 requires x-gzip and gzip encodings be treated

equivalent, similarly for x-compress and compress.  Apache
now ignores a leading x- when comparing encodings.  It also
preserves the encoding the client requests (for example if
it requests x-gzip, then Apache will respond with x-gzip
in the Content-Encoding header).

PR:		1772
Obtained from:
Submitted by:	Ronald Tschalaer <Ronald.Tschalaer@psi.ch>
Reviewed by:	Dean Gaudet, Roy Fielding (concept)


git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/branches/1.3.x@80136 13f79535-47bb-0310-9956-ffa450edef68