build.sbt: comment out initialCommands for test:console
Switch to SBT 0.12.1

I remember later SBT having more invasive changes (which broke some
project, maybe this one), so I prefer to stick with 0.12.1.
Switch back to SBT 0.12.0

Code generation already breaks with SBT 0.12.1 - probably because of
Scalate's broken classpath setup.
Switch from Scala 2.10.0 to 2.10.1 and workaround Scalac regression

"Fix" compilation with Scalac 2.10.1. Look at the comment in the diff for
details on the bug.

Among other advantages, updating Scala version might help some new crazy code
(which I have tested with 2.10.2, so I don't know if it works with 2.10.0),
which might be useful for RBI-like things.
Fix a warning introduced in Scala 2.10.1
Fix two spurious warnings introduced in 2.10.1
Add crazy code to encode parameters with a type path-dependent on an implicit parameter

While discussing macros and my old proposal
(http://blaisorbladeprog.blogspot.de/2013/01/flexible-implicits-from-agd
a-for-scala.html)
Miles Sabin came up with an alternative encoding, and I improved it
further. This might allow the kind of tricks we need here.
Switch to Scala 2.10.2 and workaround compiler crash