Auth request: add note that proxy_cache and friends do not work. With r->header_only set upstream module will shutdown client connection in case it needs to do cache/store. Probably it's good idea to avoid setting r->header_only on auth subrequest to make cache work. On the other hand, auth subrequest then will be required to return responses with empty body in all cases, even on errors.

# (C) Maxim Dounin
# Configuration for ngx_http_auth_request_module.

ngx_addon_name="ngx_http_auth_request_module"

HTTP_MODULES="$HTTP_MODULES \
		ngx_http_auth_request_module"

NGX_ADDON_SRCS="$NGX_ADDON_SRCS \
		$ngx_addon_dir/ngx_http_auth_request_module.c"