Use fixed sha1 for building shapeless 2.

The latest commits in scala-2.11.x broke spray. Let's use fixed sha1
until we figure out how to build both shapeless 1.2.4 (dependency of
spray) and shapless 2 in community build.
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.
Merge pull request #33 from gkossakowski/sbt-0.13.2

Sbt 0.13.2
Downgrade to sbt 0.13.2-M1

The sbt 0.13.2 has some Ivy-related regression that makes dbuild fail.
The sbt 0.13.2-M1 appears to work fine and includes name hashing so we
can support projects that switched to name hashing incremental compilation
mode.
Merge pull request #34 from gkossakowski/sbt-0.13.2-M1

Downgrade to sbt 0.13.2-M1
dbuild runner for the 2.12 community build
Merge pull request #35 from retronym/topic/2.12

dbuild runner for the 2.12 community build
Comply with changes to Scala's branching

  - Explicitly use scala/scala#2.11.x as the git ref for Scala
  - Remove the GenBCode configuration. It has drifted out of date
    an we need to take another pass at it, hopefully finding a means
    to avoid duplication with the regular dbuild.
Merge pull request #36 from retronym/topic/branchy

Comply with changes to Scala's branching
Bump version to SBT 0.13.5-RC2

> On Sat, May 10, 2014 at 1:06 PM, Grzegorz Kossakowski <grek@typesafe.com> wrote:
> I reproduced the problem. It's due to the fact that we are using
> sbt 0.13.2-M1 in dbuild which doesn't include a bug fix for the
> issue we ran into.
>
> Upgrading to sbt 0.13.5-RC2 restores dbuild stability.
Merge pull request #37 from retronym/topic/sbt-0.13.5-RC2

Bump version to SBT 0.13.5-RC2
Change reference to scala-arm

Trying to fix:

  https://jenkins-dbuild.typesafe.com:8499/job/Community-2.11.x/138/console
Merge pull request #38 from retronym/topic/arm

Change reference to scala-arm
Allow global injection of compiler options

This will enable broad integration testing of `-Ydelambdafy:method`
and `-Ybackend:GenBCode`.

Attempting to use the built in SBT command:

   `set every scalacOptions := scalacOptions.value ++ extraOpts`

Fails pretty quickly with:

	[info] [error] Cyclic reference involving
	[info] [error]    {file:/Users/jason/code/community-builds/target-0.8.1/extraction/7f33a0a4fdb97adf988ba940c3ec7b135ab51338/projects/556be960de41f6008705036c884135862fecf3d9/}json4s/*:scalacOptions
	[info] [error]    */*:scalacOptions
	[info] [error] Use 'last' for the full log.
	[error] java.lang.RuntimeException:
	[error] 	at scala.sys.package$.error(package.scala:27)

But, I took a look at the implementation of `set` in SBT, and figured
out how to roll my own.

The result is a custom command that lets us express this pseudo SBT:

  val releventScopes = scopes.filter(_.defines(scalacOptions))
  buildSettings += releventScopes.map {
    scope => scalacOptions in scope += extraOptions
  }

This commit does not bootstrap the compiler under the
provided options. I tried the following, but this failed when
I passed multiple options, as I must got the escaping wrong:

   extra.build-options: ["-Dlocker.skip=1", "-Ddocs.skip=1", "-Dscalac.args=\""${vars.scalacOptions}"\""]
Merge pull request #39 from retronym/topic/delambdafy-bcode

An attempt to globally configure all builds to use `-Ydelambdafy:method` and `-Ybackend:GenBCode`.
Updates to the community build files

- modified the change of vars.base.extra.commands, so that the
original definitions of vars.base and vars.base.extra in
the community*.dbuild files are preserved

- added scoverage, now needed by specs2

- added scala-logging-slf4j and scala-logging-api (v2.1.2),
needed by scoverage

- updated 0.13.5-RC2 to 0.13.5 final (RC2 has been withdrawn)

- disabled root subproject in sbt, to work around the change
in publishing mechanism (now using Release)