new config option: compression_encoding (integer)
1 - use deflate if available (or raw deflate for Internet Explorer) or don't compress
2 - use gzip if available or don't compress
10 - prefer deflate -- use deflate (or raw deflate for IE) if both deflate and gzip are available
20 - prefer gzip -- use gzip if both deflate and gzip are available
default: 20
git-svn-id: svn://ttmath.org/publicrep/winix/trunk@727 e52654a7-88a9-db11-a3e9-0013d4bc506e