Sort files by length ASC

It is useful to fix a race condition when a two or more filenames share the same postfix. `Foobar.js` and `mobile-Foobar.js` sometime `Foobar.<hash>.js` would replace `mobile-Foobar.js`.
removed buggy line
Tests are fixed
Adding testings
Removed old files
Merge pull request #33 from crodas/sort-files-by-length

Sort files by length ASC