* opgen/README
	updated TODO section.

	* opgen/geglopgen.dtd
	added prepare element.

	* opgen/Gegl/Config.pm
	Changed enum names.

	* opgen/Gegl/XML/PointOp.pm
	* opgen/Gegl/PointOp.pm
	made the prepare function customizable

	* opgen/Gegl/PointProcessor.pm
	removed the mask_mask calculation. fixed some bugs.

	* gegl/Makefile.am
	* gegl/gegl-n-src-op.gob
	New file that operators created with opgen use as a base class.