fix serving of needles

For this we need the base directory of the needle files for the distri,
so I return it as part of the needle informations
readd result borders

I mismerged mine and Dominik's changes
Merge pull request #35 from coolo/fix_needles

fix serving of needles
Merge pull request #37 from coolo/fix_css

read result borders
only force saveAs for .iso files
Merge pull request #36 from coolo/fix_download_links

only force saveAs for .iso files
remove perl-magick dependency

and with it the requirement for sudo in .travis
add prescaled thumbs to the test fixtures

We only need one of them, but it's better to have consistent test results
fix test suite - thumbs are now fixed size