* unif.c (scm_bitvector_release): Added explicit call to

* unif.c (scm_bitvector_release): Added explicit call to
scm_remember_upto_here_1.

(scm_uniform_vector_elements,
scm_u8vector_elements, etc): Made return value "const".
(scm_uniform_vector_writable_elements,
scm_u8vector_writable_elements, etc): New.
(scm_uniform_vector_release, scm_uniform_vector_release_elements):
Renamed former to latter.  Added explicit call to
scm_remember_upto_here_1.
(scm_frame_uniform_vector_release,
scm_frame_uniform_vector_release_elements): Renamed former to latter.
(scm_uniform_vector_release_writable_elements,
scm_frame_uniform_vector_release_writable_elements): New. Takes
crown of longest identifier yet.
Changed all uses as required by the changes above.