* test/merge-pp.sdf.ref: Rename as...
	* test/merge-pp.def.ref: Make definition.
	* test/merge.sdf: Rename as...
	* test/merge.def: Make definition.
	* test/merge.test: Update.

	* lib/sdf-pgen/Makefile.am: New. Extract Sdf2-pgen2.0 grammar from
	the definition file.

	* lib/Makefile.am (SUBDIRS): Update.
	* configure.ac: Update.

	* src/syn/unrename.sh: Delete.

	* test/defs.in, lib/ppgen/sdf-2-pp-lib.str,
	* src/pp/pp-boxedsdf.str, src/boxed2pp-table/boxed2pp-table.str,
	* src/syn/BoxedSdf2.str, src/syn/Makefile.am, src/syn/BoxedSdf2.sdf,
	* src/pack-boxedsdf/pack-boxedsdf.str,
	* src/boxedsdf-merge/boxedsdf-merge.str,
	* src/parser/parse-boxedsdf-module.str,
	* src/parser/parse-boxedsdf-definition.str,
	* src/boxedsdf-update/boxedsdf-update.str:
	Update to the Sdf2-pgen2.0 grammar.