JSDebugger: Break on Exception

The debugger breaks on Javascript exception. The error message is
printed on the ScriptConsole and the relevant code is marked with
a wavy underline.

Change-Id: I5e6f603430c3b8a0db450d1e8c821714ec0140ab
Reviewed-on: http://codereview.qt-project.org/4276
Reviewed-by: Qt Sanity Bot <qt_sanity_bot@ovi.com>
Reviewed-by: Leandro T. C. Melo <leandro.melo@nokia.com>
Reviewed-by: Kai Koehne <kai.koehne@nokia.com>

src/plugins/texteditor/basetexteditor.h

@@ -398,6 +398,7 @@ public:
         OtherSelection,
         SnippetPlaceholderSelection,
         ObjCSelection,
+        DebuggerExceptionSelection,
         NExtraSelectionKinds
     };
     void setExtraSelections(ExtraSelectionKind kind, const QList<QTextEdit::ExtraSelection> &selections);