* gc.c (SCM_INIT_HEAP_SIZE): Changed from 32768 --> 40000 so that

* gc.c (SCM_INIT_HEAP_SIZE): Changed from 32768 --> 40000 so that
all of Guile basics fits into one segment and there suitable room
for work.
(SCM_EXPHEAP): Now takes an argument.  Grow by a factor of 1.5
instead of 2.
(scm_freelist, scm_freelist2): Now of type scm_freelist_t.
Freelists now contains information about object span, cells
collected and amount of cells in heap segments belonging to the
list.
(scm_heap_size, scm_gc_cells_collected): Removed.