QHash<FilePath, T> may potentially crash when changing system case sensitivity

FilePath::hash() method is implemented using static method: fileNameCaseSensitivity(). Looks like it's possible, that the returned value of fileNameCaseSensitivity() may change, after e.g. user changed settings (mac only: systemsettings.cpp, line 130). That means, that it may break instances of QHash where the key is FilePath (e.g. DependencyTable::fileIndex). Provided, that we have a hash filled with FilePath items (in case sensitive mode, e.g. items like "foo.txt" and "Foo.txt"), if we change the static settings to case insensitive and then rehash that hash, we may potentially crash.