localCheckout with Git fails on Windows

Even though the MRELEASE-740 discussion mentions the solution working on Windows, we encountered a problem with releasing a subdirectory with localCheckout=true on Windows where the release plugin would just walk the tree up to the root and fail at the end, not finding the local .git directory from which to clone the repository.

This issue seems like some remaining problem in how forward- and backslashes are interpreted in the code. Or alternatively in the way the local file:// URL gets passed from the release plugin to Git.