Implement read/write and key generation; TODO encrypt/decrypt is failing with BadPaddingExceptions
encoding: Fix bug in DerNode::DerInteger for encoding the value 0.
Add symmetric key test; still haven't fixed BadPaddingSize
security: In BasicIdentityStorage added a constructor which takes the databaseFilePath.
security (minor): In PolicyManager.verifySha256WithRsaSignature, remove the TODO for moving the code.
Replace asymmetric encrypt/decrypt with UnsupportedOperationException
Rename test file and add delete key functionality
Change test author name
security: In IdentityManager, implement selfSign so that createIdentity works.
security: In IdentityManager, added setDefaultIdentity.
Merge pull request #1 from andrewsbrown/add-file-key-storage

In FilePrivateKeyStorage, implement generateKeyPair, generateKey, and encrypt/decrypt (for symmetric). Added unit test.
CHANGELOG: Added FilePrivateKeyStorage methods and TestFilePrivateKeyStorage.
security: In PrivateKeyStorage, added deleteKeyPair.
security: In FilePrivateKeyStorage.generateKeyPair, throw an exception if the keyName already exists.
security In MemoryPrivateKeyStorage, implement generateKeyPair.
security: In IdentityManager.selfSign, in the certificateName, append the current timestamp, not "0".
security: Fix bug in IdentityManager.selfSign: the certificate's KeyLocator name should be certificateName.getPrefix(-1). Just call signByCertificate.