Use random/urandom instead of C_GenerateRandom

Going through C_GenerateRandom to get random numbers is
heavy-weight and has the side-effect of bringing in PKCS#11
unnecessarily and impacting performance.

Either open /dev/random or /dev/urandom and read random
numbers from that, or call random_get_bytes or
random_get_bytes in S12.0.

When java.util.UUID.randomUUID is called, java.security.SecureRandom
uses PKCS#11 to get random numbers with C_GenerateRandom. This was
discovered by an exception thrown from an Apache app written for an
internal project.

07/01/2014 16:06:50.550 UTC idx22 ERROR Failed to index
PSARC/1994/128/IAM.UI_user-level_MT_interfaces
java.security.ProviderException: nextBytes() failed
at sun.security.pkcs11.P11SecureRandom.implNextBytes(P11SecureRandom.java:186)
at sun.security.pkcs11.P11SecureRandom.engineNextBytes(P11SecureRandom.java:135)
at java.security.SecureRandom.nextBytes(SecureRandom.java:455)
at java.util.UUID.randomUUID(UUID.java:145)