* unif.c (scm_make_uve): Removed local variable and simplified

* unif.c (scm_make_uve): Removed local variable and simplified
code in order to avoid compiler used uninitialized warnings.

* hashtab.c, hashtab.h (scm_hash_map_to_list): Renamed from
scm_hash_map.
(scm_hash_fold): Use scm_call_3 directly in the call to
scm_internal_hash_fold instead of going via fold_proc (which is
now removed).
(scm_hash_for_each): Use a trampoline +
scm_internal_hash_for_each_handle.
(scm_internal_hash_for_each_handle, scm_hash_for_each_handle): New
functions.