Removing unused PackageReceiver class.
Refactored SSL, updated crypto to modern BouncyCastle API.

Got rid of the Crypto shell class and extended the SimpleHTTPD class included in
NanoHTTPD to setup SSL automatically. The old deprecated crypto code has been
torn out. I'm reasonably confident I'm using the correct/up to date BouncyCastle
API and following best practices. The error handling definitely needs
improvement.

refs issue #2541