upgrade to Scala 2.10.2
upgrade to sbt 0.12.4
get Haskell solutions working with current ghc

at the moment on my system, that's ghc 7.6.3
Merge remote-tracking branch 'origin/master' into scala-2.11

Conflicts:
	build.sbt
upgrade to Scala 2.11.0-M4
upgrade to sbt 0.13.0-RC2

2.11.0-M4 seems to need sbt 0.13 in order for 'sbt console' to work
disable ENSIME until sbt 0.13 version is available
disable optimize, it's too fragile in 2.11.0-M4