etc/options

--- a/etc/options	Mon Nov 02 09:43:20 2015 +0100
+++ b/etc/options	Mon Nov 02 10:20:27 2015 +0100
@@ -164,3 +164,5 @@
 public option completion_limit : int = 40
   -- "limit for completion within the formal context"
 
+public option document_symbols : bool = false
+  -- "completion of Isabelle symbols within document source"