Added test to check -S
add test for ls -u
Added ls test for opt A
Added ls test for opt U
Added ls test for opt d
Removed forgotten debug output
Added ls test for opt p
added ls c option test
Removed useless stuff (some were maybe making false positives)
ls : added test to check sort options combination
add bonus tests
Merge pull request #41 from lefta/master

Bonus tests + minor corrections