Bug 225220

In 7.3 the sharable code model repository has been implemented. So far there are 2 practical ways to use it:
1) Keep it as derived object in VCS that support this sort of objects
2) Keep it aside linked to a cut of source tree and create a private copy of the cache on update (is this one practical?)

In both cases the following scenario does not work:
- I checked out some code line engaging the shared cache in some way
- I worked on a few files for a day or two
- Not checking in my modification I do an update from repository to refresh my codeline and reduce probability of troublemaking merge conflict - shared repository is updated, but code model does not reflect that parsing the modified files instead of using the available information. More than that - I did not check, but - most likely all locally introduced modifications to code model repository are gone and code model can easily be confused if not totally broken.