* discouraged.h, discouraged.c: New files.

* discouraged.h, discouraged.c: New files.

* deprecated.h (SCM_FALSEP, SCM_NFALSEP, SCM_BOOLP, SCM_EQ_P,
SCM_NEGATE_BOOL, SCM_BOOL, SCM_BOOT_NOT): Promoted from being
deprecated to being discouraged by moving to discouraged.h.

* numbers.h, numbers.c, discouraged.h, discouraged.c
(scm_short2num, scm_ushort2num, scm_int2num, scm_uint2num,
scm_long2num, scm_ulong2num, scm_size2num, scm_ptrdiff2num,
scm_num2short, scm_num2ushort, scm_num2int, scm_num2uint,
scm_num2long, scm_num2ulong, scm_num2size, scm_num2ptrdiff,
scm_long_long2num, scm_ulong_long2num, scm_num2long_long,
scm_num2ulong_long): Discouraged by moving to discouraged.h and
discouraged.c and reimplementing in terms of scm_from_* and
scm_to_*.

* numbers.h, numbers.c: Removed GUILE_DEBUG code.
(scm_i_short2big, scm_i_ushort2big, scm_i_int2big, scm_i_uint2big,
scm_i_size2big, scm_i_ptrdiff2big): Removed.
(scm_i_long2big, scm_i_ulong2big): New, explicit definitions.
* conv-integer.i.c, conv-uinteger.i.c: Use them instead of
explicit code.