Added 6px to cdnjs repo

Merging 6px into cdnjs
Merge pull request #3552 from 6px-io/master

[author] Added 6px
Updated qooxdoo's stable version to 4.0.1
Merge pull request #3559 from qooxdoo/master

Updated qooxdoo's stable version to 4.0.1 [author]