Scala 2.10.0 + smarter way to find scala jars

@eerok 

cc---

Updated Scala version of the project to 2.10.0.

Also most of us here the sbt-extras launcher (https://github.com/paulp/sbt-extras/blob/master/sbt) which helps dealing with multiple Scala/SBT versions. The Scala jar finding magic did not quite work for me, so I replaced it with something ripped of from here: http://speaking-my-language.blogspot.com.au/2009/11/embedded-scala-interpreter.html.

Do you think something like this would work?

PS. I can/will clean up the code a bit, just wanted to send an early preview.