[487151] Accept all non-conflicting changes fails to merge some diffs

Adapt diff merge computer to only return diffs that actually lead to a
conflict in the exception and not all connected diffs to ensure that
non-conflicting diffs are merged.

Includes tests.

Bug: 487151
Change-Id: I3f08e09c3e67066c57d86f572dc66a2d09ca5bb2
Signed-off-by: Martin Fleck <mfleck@eclipsesource.com>
Signed-off-by: Simon Delisle <simon.delisle@ericsson.com>
Also-by: Simon Delisle <simon.delisle@ericsson.com>
22 files changed