Creation nnn-packet.h

Created NNNPacket class to have an easier way of dealing with packet objects. Decided to reimplement the HeaderHelper::Type into nnn-packet.h using enum NNN_PDU_TYPE and ended up changing far more than I expected.

The next change will be having the packets in packets/ inherit from NNNPacket.
Headers for nnn-packet.{h,cc}
Class NNNPacket implementation

Initial implementation of NNNPacket. Next step is to make all packets inherit from the NNNPacket class.
Class AEN inheriting from NNNPacket
Indentation of AEN header file
Finished AEN inheritance of NNNPacket
Implemented inheritance of NNNPacket by DEN
Implementation of DO with NNNPacket inheritance
Passing POA_TYPES to nnn-packet.h

Indentation and using NNNPacket inheritance to the DEN and EN packets.
Removing useless whitespace
Implementation of INF with NNNPacket inheritance
Implementation of NULLp inheritance with NNNPacket
Implementation of REN with NNNPacket inheritance
Implementation of SO with NNNPacket inheritance