Updating to 2.0

Fully updated and revised for 2.0. Corrected some errors and standarized
the form of the verbs.
Remove duplicated question
Merge pull request #43 from Belelros/master

Updating ES and small fix
Fix prototypal inheritance question
Merge pull request #44 from vitorbal/patch-1

Fix prototypal inheritance question
german translation
Merge pull request #45 from DECAF/master

German
Croatian initial commit
Swedish translation+
Merge pull request #48 from Muqito/master

Swedish translation
Merge pull request #47 from msval/Croatian

Croatian  version
Update README.md

Retirado pedaço em inglês. 
Merge pull request #49 from LFeh/master

Retrieved excerpt in English
Update README_PL.md

Polish programmers often use English names for things, so they are worth adding in brackets since they are translated poorly here. I also fixed some obvious mistakes in translation and removed word “webmaster” - who on earth still uses it?
Merge pull request #50 from pim/patch-1

Update README_PL.md
Renamed French translation, WIP
Fixes spelling and semantics of the Portuguese
Culling bad questions.

Trivia-y ones that don't speak well to candidates experience. Or just old.

This needs more mobile-focused questions, and performance coverage.
Merge pull request #51 from shankarcabus/master

Fixes spelling and semantics of the Portuguese
Swedish spelling corrections