Generating lots of redirects fails with collisions.

When I attempt to use devel generate to create 30000+ redirects, it fails with an integrity constraint violation. This is just because the names of the paths are not unique enough.

I fixed this in _redirect_generate_url() by appending a string created by uniqid() to the end of:

$url[] = devel_generate_word(mt_rand(6 / $i, 8)) . uniqid();

This makes the URLs a little less pretty, but at least I can generate more than 2000 at a time (or however long it takes before colliding with another redirect).