support for v5 SHA1 UUID

[sparvu]

Using SHA-1 reduces the probability of collisions and provides a better randomness of the resulting UUID compared to V3. Can we have support for V5 UUID in Data::UUID ?

[rjbs]

We can have it if someone implements it.

[marcinpohl]

Actually if you want it to be US-govt friendly, you'd probably want to use SHA-2, SHA-1 i think is going to be deprecated by 2018. I'm not sure if there is a UUID-specific format for that or not. Just a thought.