Merge pull request #14 from filonb/nclab

highlight 'tray' keyword
Depth for input cell fix
Merge pull request #15 from martn/nclab

Depth for input cell fix
Merge pull request #16 from filonb/nclab

new Karel modes: Polish and Czech
Merge pull request #17 from filonb/nclab

new keyword: rock
Merge pull request #18 from filonb/nclab

new keyword: mark (cs, en, pl)
new languages: de, es, fr, it