fixed outputdir and added tests

I hope this time will work!
I tested it on Ubuntu and Windows 7
If it fails this time too i don't know what to say, in my case, i can set outputDir as a  relative, absolute and ./ path
and i find the compiled css where it should be..
Also try to run the test in the tests folder. It tries all the possible outputDir type of paths using a temporary dir structure.
Thanks!