fixed behaviour of non-editable textviews:

* non-editable textviews no longer draw the caret
* the cursor keys scroll immediately, not only when the (invisible) caret 
  reaches the views bounds
* HOME/END work more reliably
* any selection stays active throughout keyboard navigation
Tested with AboutSystem, Mail, StyledEdit and Beam - seems to work ok


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@30756 a95241bf-73f2-0310-859d-f6bbb57e9c96

headers/os/interface/TextView.h

@@ -394,6 +394,10 @@ private:
 
 			float				_NullStyleHeight() const;
 
+			void				_ScrollBy(float horizontalStep,
+									float verticalStep);
+			void				_ScrollTo(float x, float y);
+
 			BPrivate::TextGapBuffer*	fText;
 			LineBuffer*			fLines;
 			StyleBuffer*		fStyles;