Added crypto_policy command.

- New crypto_policy command for a single user
- New discover_crypto_policy to discover policy to existing vcards
- new crypto_policy/set command to change policy for an email
- Added gpg dependency to travis
- Added test keys to keyring, one signed and one encrypted mail
- Policy is not yet considered in compose
crypto-policy: Changes after review

- Fixed gnupg package name
- Added sign-encrypt policy
- Removed dead passphrase code
Updating result count to match new crypto-policy tests.
Fixing nose tests with new data & clamping test port range a bit more.