chg: adopt archistar-core to new crypto library

This will also change the default encrytpion to Rabin-Ben-Or.

There's a name clash between this package's CryptoEngine and the
archistar-smc CryptoEngine. I've renamed the local CryptoEngine into
ArchistarCryptoEngine. Will investigate if we can remove it altogether.
add findbugs and fix (or mark) all found "bugs"
further integrate archistar-smc and archistar-core

* remove "proxy-exceptions"
* unify ArchistarCryptoEngine and CryptoEngine
Merge branch 'master' of https://github.com/Archistar/archistar-core
Merge pull request #23 from andreashappe/master

Integrate new version of archistar-smc