Add testing root certs to an nssdb on the rootfs.

Add testing root certs to an nssdb on the rootfs.

After discussing with drewry, we can't come up with a better way to inject these root certs.  We considered putting them on the stateful partition, but that opens up an avenue of attack (if you can get a root cert into the magic directory, then you can MITM login).  Thus, we put it on the rootfs instead.  The script that sets up the hashes for vboot will verify that this directory is not present in production images.  That work is tracked here: http://code.google.com/p/chromium-os/issues/detail?id=2693

[sosa, 2010-04-19 20:54:28]

lgtm