minor optimizations

	modified:   lib/App/bmkpasswd.pm
	modified:   t/00_comparison.t
have_sha() optimizations

	modified:   lib/App/bmkpasswd.pm
minor cleanups, optimizations, POD

	modified:   Changes
	modified:   lib/App/bmkpasswd.pm
	modified:   lib/Crypt/Bcrypt/Easy.pm
	modified:   t/00_comparison.t