Fix some warnings reported by gcc.

* buddy/src/kernel.c (errorstrings): Mark these as const.
* buddy/src/reorder.c (reorder_gbc): Fix prototype.
(siftTestCmp): Add missing const in cast.
(bdd_reorder_auto): Actually call bdd_reorder_ready().

Remove more sanity checks when NDEBUG is set.

* src/kernel.h (CHECKnc): New macro.
* src/kernel.c (bdd_var, bdd_low, bdd_high, bdd_ithvar,
bdd_nithvar): Use it.

* buddy/src/kernel.c (bdd_addref, bdd_delref): Disable sanity
checks when compiled with NDEBUG.

This reverts commit d462f50b.

Conflicts:

	buddy/ChangeLog

Inline bdd_addref() and bdd_delref() to speedup BDD operations.

* src/kernel.c, src/kernel.h (bdd_addref, bdd_delref): Move these
functions and there associated global variables...
* src/bdd.c (bdd_error): ... and this function ...
* src/bdd.h (bdd_addref, bdd_delref, bdd_error): ...here so that
they can be inlined.

stderr, not stdout.  Reported by Kristin Yvonne Rozier
<kyrozier@cs.rice.edu>.

(bdd_copypair): Revert 2003-05-20's change.  Use bdd_addref
to copy result variables.

examples/Makefile.am, examples/Makefile.def,
examples/adder/Makefile.am, examples/calculator/Makefile.am,
examples/cmilner/Makefile.am, examples/fdd/Makefile.am,
examples/internal/Makefile.am, examples/milner/Makefile.am,
examples/money/Makefile.am, examples/queen/Makefile.am,
examples/solitar/Makefile.am, m4/debug.m4, m4/gccwarns.m4,
ChangeLog, INSTALL: New files.
* config, makefile, src/makefile, doc/makefile,
examples/adder/makefile, examples/calculator/makefile
examples/cmilner/makefile, examples/fdd/makefile,
examples/internal/makefile, examples/milner/makefile,
examples/money/makefile, examples/queen/makefile,
examples/solitare/makefile : Delete.
* examples/adder/adder.cxx, examples/fdd/statespace.cxx,
examples/internal/bddtest.cxx, examples/milner/milner.cxx,
examples/money/money.cxx, examples/queen/queen.cxx,
examples/solitare/solitare.cxx: Include iostream.
* examples/calculator/parser.y: Rename as ...
* examples/calculator/parser.yxx: ... this.  Remove spurious
comas in %token, %right, and %left arguments.
* examples/calculator/parser.h: Rename as ...
* examples/calculator/parser_.h: ... this, because the bison
rule with output parser.h (not tokens.h) from parser.y.
* examples/calculator/lexer.l: Rename as ...
* examples/calculator/lexer.lxx: ... this.  Include parser.h
instead of tokens.h.
* examples/calculator/slist.h
(voidSList::voisSListElem, SList::ite): Fix friend usage.
* src/kernel.h (DEFAULT_CLOCK): Default to 60 if not already
defined.
* README: Update build instruction, and file listing.