Issue171

The first commit is just a note in DEVELOPERS.txt, it always takes me a few iterations to understand why most test fails on my system...

The second one strictly fixes the issue #171 I opened.

The third one implements Jim's extra-bonus-award suggestion. Please check also the english error message, it seems ok to me, but I'm not a native speaker.

I didn't add a test against the `~/subdir` form, because it didn't seem appropriate creating/removing things in the user directory while testing... but I'm open to suggestions.