avoid explicit encoding -- acknowledge UTF-8 as global default and Isabelle/jEdit preference of UTF-8-Isabelle;

--- a/src/HOL/ex/Chinese.thy	Sun Dec 05 15:23:33 2010 +0100
+++ b/src/HOL/ex/Chinese.thy	Mon Dec 06 14:45:29 2010 +0100
@@ -1,5 +1,4 @@
-(* -*- coding: utf-8 -*- :encoding=utf-8:
-    Author:     Ning Zhang and Christian Urban
+(*  Author:     Ning Zhang and Christian Urban
 
 Example theory involving Unicode characters (UTF-8 encoding) -- both
 formal and informal ones.

--- a/src/HOL/ex/Hebrew.thy	Sun Dec 05 15:23:33 2010 +0100
+++ b/src/HOL/ex/Hebrew.thy	Mon Dec 06 14:45:29 2010 +0100
@@ -1,5 +1,4 @@
-(* -*- coding: utf-8 -*- :encoding=utf-8:  
-    Author:     Makarius
+(*  Author:     Makarius
 
 Example theory involving Unicode characters (UTF-8 encoding) -- both
 formal and informal ones.

--- a/src/HOL/ex/Serbian.thy	Sun Dec 05 15:23:33 2010 +0100
+++ b/src/HOL/ex/Serbian.thy	Mon Dec 06 14:45:29 2010 +0100
@@ -1,5 +1,4 @@
-(* -*- coding: utf-8 -*- :encoding=utf-8:  
-    Author:     Filip Maric
+(*  Author:     Filip Maric
 
 Example theory involving Unicode characters (UTF-8 encoding) -- 
 Conversion between Serbian cyrillic and latin letters (српска ћирилица и латиница)