* libguile/generalized-arrays.c (scm_array_p_2): New, formerly
`scm_array_p ()'.
(scm_array_p): Add second argument, for compatibility with 1.8 and
earlier and to match what the doc says and what `SCM_VALIDATE_ARRAY'
expects.
* libguile/generalized-arrays.h (scm_array_p_2): New.
(scm_array_p): Adjust.
* libguile/arrays.h:
* libguile/arrays.c:
* libguile/generalized-arrays.h:
* libguile/generalized-arrays.c: Move some generic functionality out of
arrays.c to a new file.
* libguile/array-map.c:
* libguile/deprecated.c:
* libguile/init.c: Update includers.
