* DataWriter.cs: Full implementation added.

* DataReader.cs: Full implementation.

* DataStream.cs: Added Flush method.
New constructor to create a copy from a DataStream.
New read/write methods.

* FileContainer.cs: Get every file contained recursively implemented.

* Format.cs: Format accepts again parameters.

* GameFile.cs: Stream property must be protected because inherited
  classes could want to modify it (add/remove metadata)
Format accepts (again...) parameters.