ComparisonUtil.getComparison(diff) where needed

Introduction of ResourceLocationChanges made this useful.
Also introduced a method that receives a Diff rather than an EObject to
avoid useless ifs when calling the method with typed Diffs.

Change-Id: Ie94e3a61c48b290ea558c5982ec839117479265f
Signed-off-by: Laurent Delaigue <laurent.delaigue@obeo.fr>
12 files changed