Merge branch '617-protocol-versioning' into 'master'

.../org/briarproject/bramble/api/crypto/CryptoComponent.java

...riarproject/bramble/api/transport/TransportConstants.java

.../org/briarproject/bramble/crypto/CryptoComponentImpl.java

.../org/briarproject/bramble/crypto/StreamDecrypterImpl.java

...iarproject/bramble/crypto/StreamEncrypterFactoryImpl.java

.../org/briarproject/bramble/crypto/StreamEncrypterImpl.java

...iarproject/bramble/transport/TransportKeyManagerImpl.java

.../briarproject/bramble/crypto/StreamDecrypterImplTest.java

.../briarproject/bramble/crypto/StreamEncrypterImplTest.java

...java/org/briarproject/bramble/crypto/TagEncodingTest.java

...va/org/briarproject/bramble/sync/SyncIntegrationTest.java

...roject/bramble/transport/TransportKeyManagerImplTest.java