Convert Digest::MD5 to object-based implementation

[coke]

Originally opened in  RT

Currently Digest::MD5 is an entirely subroutine-based implementation
and stores subs in the global namespace. It would be helpful
if it provided an object-based interface as well.

Pm

[DavidCzech]

Working on this for GCI.

[DavidCzech]

 https://github.com/parrot/parrot/pull/100 implements object interface. Going to do the same for Digest:SHA256

[bacek]

Hello.

This is wrong approach. Preferably functional interface should be implemented in terms of OO interface. And Digest::MD5 should support incremental update similar to Perl5 Digest::MD5 module.

-- Bacek

[cotto]

There's now an oo interface, so the original purpose of this ticket has been met. I agree that the procedural interface should be written in terms of the oo interface, but that's an issue for another ticket.