backport mod_deflate to lighttpd 1.4 (fixes #1824, fixes #2753)
lots of fixes and improvements
limitations: see comments at top of mod_deflate.c
missing functionality: encode streaming response
(module currently requires response be collected before being sent)
potential functionality: addition of compressed file cache would
allow mod_deflate to fully supplant mod_compress in lighttpd 1.4.x
x-ref:
"Adding mod_deflate to 1.4.xx"
https://redmine.lighttpd.net/issues/1824
"mod_deflate backport compile error if ENABLE_MMAP not defined"
https://redmine.lighttpd.net/issues/2753
github: closes #67