Begin refactoring of I/O code into FileFormat class...
...move code into new file verbatim...
...move byteArraysEqual() into Util class...
...fix imports and member visibility...
...rearrange some code...
...extract classes FileFormat.Reader and FileFormat.Writer - code now compiles but is badly indented (to make a legible diff to the last commit)...
...and finally reindent the code. No other changes. Refactoring done!