Perhaps I just missed it, but it seems to me that there is no information about the version bundled with releases of CKEditor. Although it is possible to determine the version with a regexp there's a good chance that such a routine breaks with the next release. Not being able to reliably determine the version seems to be the main cause sustainable integration of CKEditor fails in other open-source projects.
I think it would help a great deal to just put a json file in the root of future releases containing this information.
Provide Details about CKEditor in machine-readable form