Added new method to get a file mtime timestamp with the same interface as the other File* functions in Main.pm. Will be needed in Loader.
Added new method to get a file mtime timestamp with the same interface as the other File* functions in Main.pm. Will be needed in Loader.

djoudi/otrs-gitimport-test,djoudi/otrs-gitimport-test,djoudi/otrs-gitimport-test