New authentication module

[daniele-athome]

Implementing a new fast Java-based GnuPG authentication module. And dropping GnuPG entirely. Use a key-value store for fingerprint-public key mappings (that is, the keyring). The server key can be stored in a single file and will be loaded once. At that point, key ID is known so signature check should be much faster than using GnuPG (we know we have to validate signature against one key). Bouncy Castle already provides everything for parsing PGP packets so it should not be so hard.

---

Authentication:

• [x] retrieve public key block from bridge certificate
• [x] load key (if exists) from keyring and merge it (drop duplicate packets)
• [x] check for validity
  • [x] expiration
  • [x] revocation
  • [x] valid signature by the server key

---

Public key presence/publish:

• [x] retrieve public key block from keyring

---

Registration:

• [x] sign public key

---

Integration tests

• [x] install Kyoto Cabinet + jkyotocabinet
• [x] manual symbolic link for libjkyotocabinet.so (ideas?)

[daniele-athome]

Berkeley DB for Maven: http://www.oracle.com/technetwork/database/berkeleydb/downloads/maven-087630.html

[daniele-athome]

Kyoto Cabinet wrapper by last.fm: https://github.com/lastfm/lastcommons-kyoto

[daniele-athome]

Successfully online on beta as of 2015-11-15.