[Reviewer: Alex] Utils update

Alex, can you review these changes to add(/move into cpp-common) a couple of utility functions.
I've also moved some of the fake* files used in UTs into cpp-common
Although this is a backwards compatible change I think it would be a good idea to update the date stamp in `CURRENT_RESOURCE_BUNDLE` (I think support will identify the resource bundle by the date stamp so we should increment it whenever we make a non-cosmetic change.