Merge pull request #32 from gkossakowski/shapeless-regression

Use fixed sha1 for building shapeless 2.
Upgrade to sbt 0.13.2.

Sbt 0.13.2 includes name hashing which is being used (at the time this
commit is being created) by specs2 and akka. Let's upgrade to sbt 0.13.2
and unbreak community build at the same time.
Remove declaration of sbt 0.12.4.

No project in community-build is using sbt 0.12.4 anymore. Let's remove
the stale declaration of the sbt version override.
Build both shapeless 1.2.4 and shapeless 2.

Make use of spaces feature of dbuild which allows us to build multiple
versions of the same project. We build both shapeless 1.2.4 and shapeless2
that are being published into separate spaces. Although spray upstream
depends on shapeless 1.2.4 I couldn't get it to compile so we keep our
fork of spray that is upgraded to shapeless 2.

Therefore shapeless 1.2.4 is a leaf in dependency graph: no other project
depends on shapeless 1.2.4.

https://gist.github.com/gkossakowski/10277880