Calling _io().close() on ByteBufferKaitaiStream leaves open file descriptors
In the Java runtime, once a Kaitai Struct has been opened using `fromFile()` with the default stream implementation generated by the compiler, it is impossible to properly close all open file descriptors using the API. `lsof` on the Java process shows two file descriptors being opened by `fromFile()`, and only one of them gets closed when you call `_io().close()`. This is a problem because it prevents removable media from which structures have been read from being ejected until the entire process is terminated, and that is a common desirable use case for me.