* Tests for CopyTo Operation
* Changes to Matchers and Test-Utilities
* Changes to make things work
* TODO: One test still not working due to access to channel by multiple
threads
* added tests
* fixed issue in CryptoFileSystem when deleting a file
** FileContentEncryptorImpl now does not submit an empty cleartext
buffer when receiving EOF
** CryptoWritableFile now only writesHeader on close if the file is
still open
* Implemented some tests to be run on multiple implementations to
demonstrate how such tests can be implemented
* Detected problems with CryptoFileSystem(NioFileSystem)
* Made CryptoFileSystem and CryptorImpl public / constructible from
other packages
Markus Kreusch