[test] Make SiriusControlAndDeleteRepresentationTest more reliable

This test directly use resource.save(SomeOutputstream) to snapshot in
memory models.
Calling resource.save() has side-effects on the resourceset notably
setting isModified and notifying all the listeners which lead to an
unexpected amount of logic triggered because of the test behavior.

This change inhibit those side effects to have a more reliable test.

Change-Id: I2528c70d618c98154d9e524a6decba86d212780d
Signed-off-by: Cedric Brun <cedric.brun@obeo.fr>
[441483] Fix runtime errors in SWTBot test suite

The first test in the SWTBot suite,
ViewpointSpecificationProjectCreationTest, creates a plug-in project,
which triggers PDE. PDE requires PlatformAdmin to work properly, but
this was removed in Luna [1], and we did not have the workaround in
place to force the compatiblity bunde to be present.

Add the required dependency via the surefire plug-in configuration to
ensure everything needed is present at runtime (see [2]).

Also add a explicit dependencies to org.eclipse.sdk.ide and
org.eclipse.platform to the SWTBot tests plug-in, which seem to fix a
seemingly unrelated error about "Product org.eclipse.sdk.ide could not
be found." at the beginning of the tests.

[1] https://wiki.eclipse.org/Equinox/Luna_Framework#Removal_of_the_PlatformAdmin_Service_Implementation
[2] https://issues.jboss.org/browse/JBIDE-16161

Change-Id: I3661bba68cd66e9f8919624cde830c206266d207
Signed-off-by: Pierre-Charles David <pierre-charles.david@obeo.fr>