An attempt to globally configure all builds to use new backend.

In particular, `-Ydelambdafy:method` and `-Ybackend:GenBCode`.

Unfortunately this 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)

Sadly, `set every` is prone to this sort of issue.

An alternative approach will be to simply create a branch of
scala/scala in which these new backend components are enabled
by default.

This commit also did not bootstrap the compiler under the
new backend options. I removed the previous config to do this
(which had grown stale) in e2546846. From the config I removed:

    name:  "scala",
    system: "scala",
    uri:    "git://github.com/scala/scala.git#master"
    extra: {
      build-options: ["-Dscalac.args=\"-Ybackend:GenBCode\""]
    }