Update build to use Tycho 0.15.0

Also use packaging type eclipse-repository to create the p2 repository
since Tycho fixed bug 368596 which we worked around using packaging type
eclipse-update-site.

Change-Id: Id4ee884027d55cd2d43e8a6ef58a67f74ab488e4
Signed-off-by: Matthias Sohn <matthias.sohn@sap.com>
4 files changed