Premier Heart enhancements to OpenPGP Zimlet

- Support encrypting to multiple recipients.
- Support storing Private Key on server.
- Support storing Private Key Passphtrase on server.
  Use of this feature is STRONGLY DISCOURAGED!
- Update openpgp.js to 0.8.2 (new API)
  - Refactored encryption/decryption to use new API.

TODO:
  - Verify signature verification using new API
    (May require more code changes)
  - Sign encrypted messages by default
    (or add "Encrypt & Sign" option)