Update Passage Oomph setup

[ruspl-afed]

There several things to be done:

• remove of find proper repository for org.eclipse.emf.ecoretools.sdk.feature.group
• add simrel repo
• add org.eclipse.cbi.p2repo.aggregator.editor.feature.feature.group

And more findings from @merks

• Ensure that a proper API baseline is populated.
• Ensure that nested projects are imported.
• Configure forked branches to use rebase by default.

[ruspl-afed]

Now it works better, thanks to @merks
The only issue I see is: one need an extra restart to apply target and baseline (double checked)