During version merge an affects version or fix for version will be set even if it is not required

When figuring out what issues are affected when merging versions, all issues (whether they have the affects version or fix for version) are put into a single collection.

When looping through the issues we remove the version which is about to be deleted and add the version we are trying to swap for. The problem is that sometimes we erroneously add the affects for version or fix fir version to the issue. That is, we do not check whether the version that is being deleted is actually set for the particular version field before we add the swap version.

The net affect is that when version are merged the new version is set for both the affects version and fix for version, while for some issues it should only be set for one of them.