Upgrade to Scala 2.11.0-M6.

[gkossakowski]

That entails tweaking dependencies once again. Hold your breath:

• we can't upgrade to new version of partest because it's not been
  released yet; we can't release it first because scalacheck is needed
• therefore we are using the M5 version and then we have to exclude
  all transitive dependencies that were built against M5; one such
  dependency would be scala-compiler itself
• since we excluded all transitive dependencies we need to bring some
  back: we add diffutils and scala-compiler but M6 version

All newly added dependencies are in "test" scope. I verified that nothing
leaks to a pom.xml.

Also, updated check file for one of the tests because there were some
improvements to error handling that changed errors being emitted. See
SI-7895 for details.

[gkossakowski]

Review by @adriaanm or @retronym.

Once this patch is merged I'll go ahead and release a new version of scala-xml based on this commit. Having learnt my lesson, I won't be applying any non-trivial patches prior to cutting the release without a review.

[adriaanm]

does this support wildcards? "scala-xml_.*"?

[gkossakowski]

I don't think so but I would have to check. I'll remember to do that.

[gkossakowski]

In [sbt's documentation[(http://www.scala-sbt.org/release/docs/Detailed-Topics/Library-Management#exclude-transitive-dependencies) there's ExclusionRule mentioned briefly but there's no information anywhere whether it supports wildcards or not. Also, wildcards are not supported by Maven so I would rather not use them because they can't be incorporated in poms we generate.

[adriaanm]

LGTM (modulo review comments)

I'm surprised partest works when its dependency is in the "test" config, but I'm assuming you verified that you can run test.

[gkossakowski]

Yes, I did run partest and that's how I discovered I have to update the check file. :)