* tags.h (SCM_CONSP, SCM_NCONSP): Define these in terms of

* tags.h (SCM_CONSP, SCM_NCONSP): Define these in terms of
SCM_SLOPPY_CONSP and SCM_SLOPPY_NCONSP.  (SCM_CONSP) Define this
in terms of SCM_SLOPPY_NCONSP instead of repeating the
expression.

* symbols.h (SCM_SLOPPY_SUBSTRP, SCM_SUBSTRP): Added former, and
define latter in terms of sloppy variant.

* strings.h (SCM_SLOPPY_STRINGP, SCM_STRINGP): Added former, and
define latter in terms of sloppy variant.

* scm_validate.h (SCM_MAKE_VALIDATE): Added this macro to factor
out the commonality of the various basic SCM_VALIDATE_foop
macros. Use SCM_MAKE_VALIDATE macro where possible.  Fix
SCM_VALIDATE_INT_COPY to not use scm_num2ulong -- that does
coercion to an integer which is more advanced than desired and
SCM_NUM2ULONG provides that functionality.  Use SCM_ASSERT_RANGE
appropriately for the various _MIN, _MAX, _RANGE macros.  Drop
some superfluous "SCM_NIMP &&" where possible. Eliminate obsoleted
SCM_VALIDATE_NIMCONS (SCM_VALIDATE_CONS now does the NIMP test as
part of its SCM_CONSP test).

* socket.c, ports.c, pairs.c, list.c, lang.c, async.c: Use
SCM_VALIDATE_CONS, not obsoleted SCM_VALIDATE_NIMCONS.