Merge branch 'ticket/bantu/9790' into develop

* ticket/bantu/9790:
  [ticket/9790] Support for lighttpd's X-Sendfile header for attachments.
  [ticket/9790] Support for nginx's X-Accel-Redirect header for attachments.
  [ticket/9790] Always call file_gc(false) before sending the file.
  [ticket/9790] Add $exit parameter to file_gc().

phpBB/docs/lighttpd.sample.conf

@@ -3,6 +3,15 @@
 # from your system's lighttpd.conf.
 # Tested with lighttpd 1.4.26
 
+# If you want to use the X-Sendfile feature,
+# uncomment the 'allow-x-send-file' for the fastcgi
+# server below and add the following to your config.php
+#
+#  define('PHPBB_ENABLE_X_SENDFILE', true);
+#
+# See http://blog.lighttpd.net/articles/2006/07/02/x-sendfile
+# for the details on X-Sendfile.
+
 # Load moules
 server.modules += ( 
 	"mod_access",
@@ -54,6 +63,7 @@ $HTTP["host"] == "www.myforums.com" {
 			"bin-copy-environment" => (
 				"PATH", "SHELL", "USER"
 			),
+			#"allow-x-send-file" => "enable",
 			"broken-scriptfilename" => "enable"
 		))
 	)

phpBB/docs/nginx.sample.conf

@@ -3,6 +3,14 @@
 # from your system's nginx.conf.
 # Tested with nginx 0.8.35.
 
+# If you want to use the X-Accel-Redirect feature,
+# add the following to your config.php.
+#
+#  define('PHPBB_ENABLE_X_ACCEL_REDIRECT', true);
+#
+# See http://wiki.nginx.org/XSendfile for the details
+# on X-Accel-Redirect.
+
 http {
     # Compression - requires gzip and gzip static modules.
     gzip on;