CMake: Duplication of Run configurations

Steps to reproduce:

• open an existing cmake based project with QC 4.6.x (remove any .user files before opening)
• check and remember the targets that are listed on the Run Settings side (or inside the mini target selector)
• close the project and QC (it's not necessary to build anything - just open & close correctly to have the .user file created)
• now open the same project with QC 4.7 and check the targets again

Current result:

• all of the targets are listed twice (same name, but with '2' as suffix)
• the original targets (created with 4.6.x) are marked as "The project no longer builds the target associated with this run configuration." inside the run settings

Some investigation showed this is mainly due to an internal change of the buildKey which in turn lets the restored targets appear as different compared to the automatically generated ones while parsing.

I've got a local (hacky) patch that would make the above scenario work, but apparently this of course breaks when re-opening the project afterwards with a QC 4.6 again.

I'm not sure whether this approach can get handled correctly at all (I do not get any warning of using an outdated or too new .user file, which I'd expect to "solve" this as well as this normally resulted in ignoring the .user file(s) completely and starting basically from scratch)