* subversion/libsvn_subr/config_file.c
(svn_config_ensure): Move 'compression' into the "servers" file as
'http-compression'.
* subversion/libsvn_ra_dav/ra_dav.h
(svn_ra_session_t): Add 'compression'. Remove 'config'.
* subversion/libsvn_ra_dav/session.c
(get_server_settings): Add 'compression', and parse for compression
settings on a per-server basis.
(svn_ra_dav__open): Update call to get_server_settings().
* subversion/libsvn_ra_dav/fetch.c
(custom_get_request): Remove 'config', add 'compression'.
(simple_fetch_file): Remove 'config', add 'compression', and update
call to custom_get_request().
(fetch_file): Remove 'config', add 'compression', and update call to
simple_fetch_file().
(svn_ra_dav__get_file): Update call to custom_get_request().
(svn_ra_dav__do_checkout): Update call to fetch_file().
(start_element, end_element): Update call to simple_fetch_file().
* subversion/libsvn_ra_dav/util.c
(svn_ra_dav__parsed_request): Get the compression info from the
session baton.
* doc/book/book/ch06.xml
Update to reflect move of 'compression' option into the 'servers' file.
