* snarf.h: Drop SCM_PROC, SCM_PROC1. Added extra output for

* snarf.h: Drop SCM_PROC, SCM_PROC1. Added extra output for
guile-doc-snarf script.

* guile-doc-snarf.in, guile-doc-snarf.awk: New, simple doc
extraction system.  Builds foo.x, foo.doc from foo.{c,cc}.
There are dependencies between these files and snarf.h.  This
replaces guile-snarf.

* guile-snarf.in: Drop everything after $$$ for the new snarf.h
macros.  This is obsoleted by guile-doc-snarf, but kept here for
now for good measure.

* Makefile.am: Added guile-doc-snarf, guile-doc-snarf.awk to
bin_SCRIPTS.  Added .doc to SUFFIXES, and give rule for creating
.doc files to use guile-doc-snarf.  Update the rule for creating
.x files to use guile-doc-snarf.