#33: Added implementation without nio2. Detail work was in
copy/move/delete operations with focus of similiar behaviour.
Added parametrized test for comparison of both implementations
(*.oio.test). Inside a new test-project, which has both implementations.
Removed some unnecessary return types from File interface.
Added another simpler FileUtils class for relativePath, which behaves
more like java.nio.Path.relativize(Path).
Removed FileChannelFactory: after evaluation of robovm-rt-0.0.14.jar
it's expected to have the old java.nio packages and the tryLock function
is available.