Add Nexus repository URLs to enable publishing build artifacts

Signed-off-by: Matthias Sohn <matthias.sohn@sap.com>
Bug 408190 - Action selections are created every time a selection is changed in the sidebar in the editor view
Bug 408190 - Action selections are created every time a selection is changed in the sidebar
Bug 399023 - Add a p2 repository for assembling client bundles

This is required to consume the result of the orion client build from
the orion server build which runs in a different Hudson job since Tycho
can only consume bundles from another build via a p2 repository.

Assembling bundles directly into a p2 repository requires that we update
to use Tycho 0.17.

Signed-off-by: Matthias Sohn <matthias.sohn@sap.com>