Updated script to be able to build master

After master has moved to Sbt 0.13.0-RC3 (see
scala-ide/scala-ide@5cd2a35963b27f9569660d17de7948122d44f2f), the uber-build
had to be updated to use Sbinary v0.4.2-SNAPSHOT.
(cherry picked from commit 764bfa09db564822d27b0db2024a825709d3763b)