* environments.c (DEFAULT_OBARRAY_SIZE): Changed from 137 to 31

* environments.c (DEFAULT_OBARRAY_SIZE): Changed from 137 to 31
(since hash tables now adapt their size).

* modules.c (scm_modules_prehistory): Changed from 2001 to 1533
(current number of prehistory bindings; hashtable code will select
a prime which is greater than this value).

* symbols.c (scm_symbols_prehistory): Changed from 1009 to 2139
(current number of initial symbols).

* properties.c (scm_init_properties): Don't specify size of
scm_properties_whash.

* objprop.c (scm_init_objprop): Don't specify size of
scm_object_whash.

* keywords.c (scm_init_keywords): Don't specify a hash table size.