(SCM_ARRAYP, SCM_I_ARRAYP): Renamed former to latter internal

(SCM_ARRAYP, SCM_I_ARRAYP): Renamed former to latter internal
version.  Changed all uses.
(scm_tc16_array, scm_i_tc16_array,
scm_tc16_enclosed_array, scm_i_tc16_enclosed_array,
SCM_ARRAY_FLAG_CONTIGUOUS, SCM_I_ARRAY_FLAG_CONTIGUOUS,
SCM_ENCLOSE_ARRAYP, SCM_I_ENCLOSE_ARRAYP,
SCM_ARRAY_NDIM, SCM_I_ARRAY_NDIM,
SCM_ARRAY_CONTP, SCM_I_ARRAY_CONTP,
SCM_ARRAY_MEM, SCM_I_ARRAY_MEM,
SCM_ARRAY_V, SCM_I_ARRAY_V,
SCM_ARRAY_BASE, SCM_I_ARRAY_BASE,
SCM_ARRAY_DIMS, SCM_I_ARRAY_DIMS,
scm_t_array, scm_i_t_array): Likewise.
(SCM_SET_ARRAY_CONTIGUOUS_FLAG, SCM_CLR_ARRAY_CONTIGUOUS_FLAG):
Moved from unif.h to unif.c.
(scm_c_array_rank): New.
(scm_array_rank): Reimplement using it.