Update AES-CBC encryption

[Justin Richer]

The latest JOSE specs have changed encryption method used with AES-CBC algorithms and we need to update.

[Vladimir Dzhuvinov]

Thanks, I got Mike's announcement of the new spec release.

I'm going to have next week off, I'm going on a holiday, so I won't be able to look at this stuff before the second week of May.

[Justin Richer]

There's no rush on the implementation changes from our end, I just wanted to make sure they didn't get forgotten.

[Vladimir Dzhuvinov]

Good :)

[Vladimir Dzhuvinov]

Update completed in commit c0c9493 .