Add Cryptopp Code

OSTC 3 Firmware update requires Cryptopp to decrypt the firmware
file. The added line in subsurface.pro imports the Cryptopp code.

Currently, I have put this code outside Subsurface's source code,
as I look for a better way to link the library, or if possible to
use libcrypto.

Signed-off-by: Joseph W. Joshua <joejoshw@gmail.com>