Akka master on Scala master
Merge pull request #6 from bantonsson/wip-akka-master-on-scala-master-ban

Akka master on Scala master
Add spray to dbuild configuration.

Spray depends on Play2-Json so I kept Play definition around and just
changed it to build the specific subproject.

This doesn't build yet.
Merge branch 'play' into spray
Add parboiled and spray-jason
Add lift-json to dbuild.

Lift has a bit crazy build split into two repos that I both had to fork.
See commit messages in those forks for details.
Add spray-twirl-api to dbuild.
Add json4s to dbuild configuration.

Based on my fork, see the comments and commits in my fork for reasons
why I had to fork.
Disable tests and running sphinx in spray.
Switch back to tracking sbt's 0.13 branch.
Merge remote-tracking branch 'retronym/jenkins' into spray
Build the whole Play2-core again.

For spray we needed just Play-Json but now that we are preparing for
merging upstream, let's build entire Play2-core.
Merge pull request #7 from gkossakowski/spray

Add Play2-core, spray, scala-async and many more
Merge branch 'master' into jenkins
Centralize git-refs for repositories

Since dbuild's long-term goal is to require only a list of github url's
to build, lets already encode that in our configs, so that the header
tells you what's being built, and everything below that is hackery
to deal with imperfections in the various builds/dbuild.

I verified the following PRs were merged, so I changed the refs to
the corresponding branches:
```
etorreborre/specs2.git#master -> etorreborre/specs2.git#pull/238/head
milessabin/shapeless.git#pull/80/head -> milessabin/shapeless.git#scala-2.11.x
```

I double-checked the patch, which is the result of the following regex hack:

- create the vars section: `s|([\w-]+)/([\w-]+)(#.*\")?|$2-ref: "$1/$2$3"|`
- replace uri's by standardized `"https://github.com/"${vars.$2-ref}`:
`s|/([\w-]+)/([\w-]+)(#.*\")?|/"{vars.$2-ref}|g`
Cleanup. Centralize SBT version overrides.
Moved comments describing forks to vars, sorted.
Override repos, needed to add spray.io repo.