Updated script to no longer build sbt and sbinary

Thanks to dbuild, we are no longer in need of building sbt/sbinary artifacts
ourselves, as we can consumes the ones built by dbuild.

This commit is related to https://github.com/scala-ide/scala-ide/pull/472
Added the additional profile new-sbt when building IDE

This was needed to accomodate
scala-ide/scala-ide@fa5aea7800a842a43af01b7fc14e23d554720548, and can be reverted once we
eliminate the need of the additional sbt profile.
Merge pull request #10 from dotta/build/use-dbuild-sbt-artifacts

Build/use dbuild sbt artifacts