CAY-1925 cayenne-crypto: add optional compression to the encryption pipeline

splitting Header into a separate class

git-svn-id: https://svn.apache.org/repos/asf/cayenne/main/trunk@1586977 13f79535-47bb-0310-9956-ffa450edef68
CAY-1925 cayenne-crypto: add optional compression to the encryption pipeline

proper name for header encryptor and decryptor

git-svn-id: https://svn.apache.org/repos/asf/cayenne/main/trunk@1586978 13f79535-47bb-0310-9956-ffa450edef68
CAY-1925 cayenne-crypto: add optional compression to the encryption pipeline

using the new Header class in byte encryptors

git-svn-id: https://svn.apache.org/repos/asf/cayenne/main/trunk@1586979 13f79535-47bb-0310-9956-ffa450edef68
CAY-1925 cayenne-crypto: add optional compression to the encryption pipeline

using the new Header class in byte decryptors

git-svn-id: https://svn.apache.org/repos/asf/cayenne/main/trunk@1586980 13f79535-47bb-0310-9956-ffa450edef68
CAY-1925 cayenne-crypto: add optional compression to the encryption pipeline

a more complex header structure: magic #, size, flags, key_name

git-svn-id: https://svn.apache.org/repos/asf/cayenne/main/trunk@1586981 13f79535-47bb-0310-9956-ffa450edef68