Clean up Scala distribution a bit.

Prompted by https://issues.scala-lang.org/browse/SI-4248, 
which pointed out we should include doc/licenses in the binary dist,
I finally decided to clean up the dist a bit -- even for 2.10.x.

No more:
- partest in the binary dist
- redundant examples in scala/scala -- they actually come from scala/scala-dist
- references to windows 95 in our readme
- unused android test

Also added the Typesafe attribution that was agreed on earlier.

Review by @retronym, /cc @heathermiller, @gkossakowski, @jsuereth