Add c++ crypto wrapper from https://github.com/aldrin
Add aes_armor.
New byte_array operations make casts nicer.
Strip-off HMAC from the decoded message.
Simplify armor code using new byte_array functions.
Add aes_armor.
Update function documentation in aes_armor.
Fix include paths.
Fix include paths.
Compress crypto related classes into 'crypto' namespace.
Compress crypto related classes into 'crypto' namespace.
Rename krypto header to avoid clashes with openssl crypto.
Bring in the aes_armor.h from libkrypto, where it doesn't belong.
Pull in aes_armor.cpp from libkrypto where it doesn't belong.
Put aes_armor in ssu namespace.