translate config server.modules "mod_compress" to "mod_deflate"
accept compress.* directives, but issue DEPRECATED warning trace
mod_deflate differences from mod_compress:
- mod_compress compress.filetype was exact match; deflate.mimetypes is
prefix match (behavior change might compress longer mimetype matches,
which are likely of similar type and compressability)
- mod_compress always sent entire (compressed) file for Range request
mod_deflate will stream compress range result (not stored in cache)
- mod_compress would short-circuit request with 403 Forbidden error
if request file did not exist (stat() failed) (This behavior was
unfriendly to other handlers)
- mod_compress compress.cache-dir layout differs from deflate.cache-dir
layout; file cache should be cleared (or renamed) when migrating from
mod_compress to mod_deflate
- mod_deflate does not issue Vary: Accept-Encoding if request does not
contain Accept-Encoding. The identity response can be cache by
proxies and served to clients. Historically, some proxies disabled
caching if any Vary: response was seen. If the Vary header is
desirable, mod_deflate code which checks for Accept-Encoding and
compression type can be moved down a few lines to be below the
setting of the Vary response header.