Fix injection of vm parameters to server tests

This allows to inject e.g. proxy settings to the VM running the tests by
setting the Maven property "test.vmparams"

$ mvn clean install -Dtest.vmparams="-Dhttp.proxyHost=myhost -Dhttp.proxyPort=8080"

This worked earlier and was broken in 42f3c366.

Change-Id: Iaa758b822fcd10b505e1d518b5adb9efa2ce5067
Signed-off-by: Matthias Sohn <matthias.sohn@sap.com>
Bug 443795 - o.e.o.server.tests broken with Tycho 0.21

Tycho 0.21 resolves surefire dependencies more strictly, i.e.
the version argument 0.0.0 does no longer match "any available
version" (see Bug 436617 for details). This leads to unresolved
dependencies during the build.

This patch follows the advice given in Bug 436617 and declares the
test dependencies in a separate configuration section for the
target-platform-configuration.

The dependency to org.eclipse.orion.releng.test.master has been
removed since Tycho reports a dependency cycle, and the dependency
was obsolete anyway.

Change-Id: I2dc663a93a4fc1150c48e4286f5cfcd8128cf318
Signed-off-by: Michael Ochmann <michael.ochmann@sap.com>