In blist.h, BLIST_BMAP_RADIX and BLIST_META_RADIX have the same

value. There's no longer a need for both names, so rename them both to

BLIST_RADIX. Simplify formulas that compute with both of them, and

rewrite comments that describe them.

Make a similar change for BLIST_BMAP_MASK and BLIST_META_MASK.

In blist_create, modify the use of the variable radix so that it takes

on values 1, 64, 4096, ... instead of 64, 4096, 262144, ..., in order

to avoid overflow when the next power of 64 greater than blocks is too

big to represent. The value of bl->bl_radix is similarly reduced by a

factor of BLIST_RADIX.

Change the blist_meta_* functions that take a radix parameter to

handle one reduced by a factor of BLIST_RADIX. When necessary, handle

overflows in masking off all but the first radix*BLIST_RADIX bits of a

number, when that's masking off all the bits.

Fix compiler warnings in blist test code. Add a test for blist_create

failure to the blist test code. Change the blist_test code size

parameter to allow for larger test cases.

Remove from swaponsomething the checks for overflow in the blist

code. The only failure I can think of is from a failed malloc.