bypass input method for better imitation of read-only mode (cf. f26a4d5e82b5): e.g. relevant for composition of ALT-u u on Mac OS X;

--- a/src/Tools/jEdit/src/pretty_text_area.scala	Wed Jan 20 15:22:18 2016 +0100
+++ b/src/Tools/jEdit/src/pretty_text_area.scala	Wed Jan 20 19:19:33 2016 +0100
@@ -12,6 +12,7 @@
 
 import java.awt.{Color, Font, Toolkit, Window}
 import java.awt.event.KeyEvent
+import java.awt.im.InputMethodRequests
 import javax.swing.JTextField
 import javax.swing.event.{DocumentListener, DocumentEvent}
 
@@ -224,6 +225,8 @@
 
   /* key handling */
 
+  override def getInputMethodRequests: InputMethodRequests = null
+
   inputHandlerProvider =
     new DefaultInputHandlerProvider(new TextAreaInputHandler(text_area) {
       override def getAction(action: String): JEditBeanShellAction =