Aes wip

Hi Luke, It has been too long since I did an update. However I've:-
* Managed to get CTR encryption scheme also going.
* I've also removed initial encrypt/decrypt 'test' code.
* Done some testing with various configs 

FYI:-
- S16 = 0 = no encryption
- S16 = 1 = 128bit CBC
- S16 = 2 = 192bit CBC
- S16 = 3 = 256bit CBC
- S16 = 17 = 128bit CTR
- S16 = 18 = 192bit CTR
- S16 = 19 = 256bit CTR