refine CMPH and make Hanov/Urban->hash a method

Hanov->hash (crc32) is now a bit slower, but we can share it with Urban.
return an arrayref for CMPH objects to hold options.
allow options to examples/bench.pl
fix the Hanov @ISA
make the c hashs funcs static inline
support optional -nul for t/04save_c.t
upgrade from -O2 to -O3 in c tests.