some kawa i/o classes moved to new package

[Per Bothner]

The various Kawa Reader/Writer classes (including InPort and OutPort)
where spread out in a confusing way among the gnu.text and gnu.mapping
packages.  I moved these to a new package gnu.kawa.io, which should 
hopefully
be less confusing.  I will probably also move the gnu.text.*Path classes
to gnu.kawa.io.

This change might break source compatibility if you use the Java classes
directly.  Even if you don't, they might break binary compatibility,
because (say) input-port is now a different class.

I'm also considering removing LineBufferedReader (merging its functionality
directly into InPort), and also LineInputStreamReader (merging its
functionality into BinaryInPort).  This should make things slightly simpler.
-- 
	--Per Bothner
per@bothner.com   http://per.bothner.com/