text viewer: reworks screen access logics and some bugs fix.

- screen access logics separte from tv_window. (new tv_display.[ch])
- using multi screen api.
- (bug fix) the head of the each line is not normally displayed when the alignment is RIGHT.
- (bug fix) unnecessary blank line is not displayed. (a part of FS#11400).
- (bug fix) the order by which callback functions were called was not correct. (FIFO->FILO)

git-svn-id: svn://svn.rockbox.org/rockbox/trunk@27138 a1c6a512-1295-4272-9138-f99709370657

apps/plugins/text_viewer/tv_preferences.c

@@ -62,7 +62,8 @@ static void tv_notify_change_preferences(const struct tv_preferences *oldp)
 #endif
         (rb->strcmp(oldp->file_name, preferences->file_name)))
     {
-        for (i = 0; i < listner_count; i++)
+        /* callback functions are called as FILO */
+        for (i = listner_count - 1; i >= 0; i--)
             listners[i](oldp);
     }
 }