Nettle: Moved modes CTR and CCM to submodules.

CTR is now a submodule to Nettle.BlockCipher, and
CCM and CCM8 are submodules to Nettle.BlockCipher16.

Added fallback C-implementation of CTR if the Nettle library lacks one.

All common modes should now be submodules.
Change for new Crypto API.
ADT.Queue 30% faster and uses less memory.
Trivially strict_types.
Handle queue underflow.
Use local objects instead of named inherits for the packet queues.
Change datastructure to allow for more than one crypto key per DER subject.
packet -> Packet. Slowly moving towards import ".".
Improved profiling. Do we need this at all?