2003-03-12  Sven Neumann  <sven@gimp.org>

	* app/core/gimpchannel.[ch]: added gimp_channel_new_from_component()
	which creates a new GimpChannel from an image's color component.

	* app/gui/channels-commands.[ch]: added
	channels_duplicate_component_cmd_callback().

	* app/paint-funcs/paint-funcs-generic.h
	* app/paint-funcs/paint-funcs.[ch]: added code to extract a color
	component from a PixelRegion (untested!).

	* plug-ins/common/checkerboard.c: cosmetics.