FileHandles and FileStreams

[Brian T Rice]

I've updated the FileHandle interface to support the same basic protocol
as a Stream, and tests fine by itself. It also has an extended protocol
which lets it write directly into Strings or ByteArrays or ordinary
Arrays, so memory usage can be controlled. I also added some default
conversion (as: methods) to those traits to make it more sensible to use
any of them without having to convert manually.

I also updated FileStream to use it, and fixed a bug or two, but there are
still some remaining. I'd like to get this into working shape really soon,
but I'm very distracted at the moment with some other issues, so if
someone could try it out and find some fixes, I'd appreciate it (I suppose
I can pay back with some more features elsewhere or something ;).

-- 
Brian T. Rice
LOGOS Research and Development
http://tunes.org/~water/