Hotfix/double slashes filepath

I found a wierd bug that I only notices when automatically adding files to the gitignore. It seems PHP or the OS does not care about double slashed in paths. Eg this is a valid path: `/app/etc/modules//EcomDev_PHPUnit.xml`

This has taken me almost a day to reproduce in code, it seems this issue only occurs when the destination directory exists and the source is a glob. I've added a failing unit test and then the second commit fixes the current issue. Who knows if it breaks something else though! - however all the other tests do pass on my machine.