* gtk/gtktextview.c (gtk_text_view_move_cursor_internal): Skip
	invisible chars for GTK_MOVEMENT_LOGICAL_POSITIONS and
	GTK_MOVEMENT_WORDS.

	* gtk/gtktextiter.c,
	gtk/gtktextiter.h: Add some variant movement functions which
	skip invisible chars, and do some cleanups.

	* gtk/gtk-sections.txt: Add new GtkTextIter functions.