Bug 317954 Version deltas file so that incompatible changes will be ignored
The deltas file needs to be versioned so that incompatible changes will be discarded allowing the workbench to be constructed as if there were no deltas in existence.
bundles/org.eclipse.e4.ui.workbench/src/org/eclipse/e4/ui/internal/workbench/XMLModelReconciler.java
int afterIndex = currentReferences.indexOf(afterCandidate);
				if (afterIndex != -1) {
					after = afterCandidate;
					break;
				}
			}
			Object before = null;
			for (int i = originalIndex + 1; i < userReferences.size(); i++) {
				Object beforeCandidate = userReferences.get(i);
				int beforeIndex = currentReferences.indexOf(beforeCandidate);
				if (beforeIndex != -1) {
					before = beforeCandidate;
					break;
				}
			}
			return new Position(object, after, before);
		}
		return null;
	}
	static class Position {
		private final Object object;
		private final Object after;
		private final Object before;
		Position(Object object, Object after, Object before) {
			this.object = object;
			this.after = after;
			this.before = before;
		}
		public Object getObject() {
			return object;