eliminate recursive make invocation in examples directory tree * examples/module.mk: New file. * Makefile.am: Include examples/module.mk. (SUBDIRS): Remove examples from the list. * configure.ac (AC_OUTPUT): Don't generate examples/Makefile, examples/code/Makefile, or examples/data/Makefile. * examples/Makefile.am, examples/code/@FIRfilter/module.mk, examples/code/@polynomial/module.mk, examples/code/Makefile.am, examples/data/Makefile.am: Delete.