add external passsword quality check builtin module
add external passsword quality check builtin module

[password_quality]
	policies = external-check
	external-program = /bin/false

To approve password a, make the test program return APPROVED on stderr
and fail with exit code 0.


git-svn-id: 193148810cf65385f3a195dbc9a8b504846da3a2@14784 ec53bebd-3082-4978-b11e-865c3cabbd6b

madscientist159/heimdal,madscientist159/heimdal,madscientist159/heimdal,madscientist159/heimdal,madscientist159/heimdal,madscientist159/heimdal,madscientist159/heimdal