have_sha() trap dying calls to crypt()

	modified:   lib/App/bmkpasswd.pm
	modified:   t/03_sha.t
v1.082005

  Better passwdcmp() argument-checking

  Trap dying 'crypt()' calls in tests to avoid fuzzy fails like
  http://www.cpantesters.org/cpan/report/be021b42-9e64-11e2-8d62-e95aab8f1a3b