2005-03-09  Michael Natterer  <mitch@gimp.org>

	More sample point stuff. Addresses bug #137776.

	* app/core/gimpimage-sample-points.c
	* app/core/gimpimage-undo-push.c: append, not prepend the sample
	paints to the image's list because their index matters. Update
	sample points when their index changes.

	* app/display/gimpcanvas.[ch]: added own sytles for the sample
	points.  Added gimp_canvas_draw_text() which uses a PangoLayout
	which is cached in the canvas.

	* app/display/gimpdisplayshell-draw.c
	(gimp_display_shell_draw_sample_point): draw the sample points
	more distinct from guides using the new canvas APIs above.

	* app/display/gimpdisplayshell-callbacks.c
	(gimp_display_shell_[hv]ruler_button_press): factored out all
	code to

	(gimp_display_shell_ruler_burron_press): which takes a boolean
	"horizontal" variable and allows to add sample points with
	<control>+drag.

	* app/tools/gimpcolortool.[ch]: implement adding, moving and
	removing of sample points in the same way as the move tool moves
	guides.

	* app/tools/gimpcolorpickertool.c
	(gimp_color_picker_tool_oper_update): chain up.