Tweak build to include appropriate fixes/adaptations for Scala 2.11.0-M7

* Limit M7 hackery to one location in the build
* Migrate scala-compiler dependency declarations to use workaround for M7
* fix libModular to work with new module organizations.
* Bump versions of modules used for 2.11 build.


Review by @harrah  cc @adriaanm

Note: This does not include the type fixes in the 0.13-2.11 branch, but includes different build hackery for 2.11.  I'd like to standardize on this mechanism for dbuild (changing scalaVersion in ThisBuild fixes all deps appropriately).