wwwfind support currently for Linux only

--- a/NEWS	Fri Nov 20 15:29:56 2009 -0800
+++ b/NEWS	Sat Nov 21 11:47:38 2009 +1100
@@ -361,7 +361,7 @@
 
 * New component "isabelle wwwfind [start|stop|status] [HEAP]"
 Provides web interface for find_theorems on HEAP. Depends on lighttpd 
-webserver being installed.
+webserver being installed. Currently supported on Linux only.
 
 * Discontinued support for Poly/ML 4.x versions.