Apply workaround for bug in scripted plugin.
Use sbt 0.13.1-SNAPSHOT

If you want to test name hashing algorithm
checkout the `name-hashing` branch from
https://github.com/gkossakowski/xsbt repo.

Then just run `publish-local` and run
scripted tests from this project.
Switch to Scala 2.10.2.
Add commented out settings useful for debugging.

If you want to debug incremental compiler's
behavior uncomment those two lines.
Fix sbt version numbers.

The main project should just use sbt 0.13.0.

The scripted tests uses 0.13.1-SNAPSHOT which
is the version number used in name hashing branch.
Add some debugging output.

Added echo lines which explains what is being
compiled at the moment.
Add missing Typesafe repo.

This way we can resolve play artifacts properly.

It used to work without explicit definition but
it seems like it stopped in sbt 0.13.