Fix contract extend
Fix extend : now extend throws Error if extending unexisting service
Fix "\" in documentation (from PHP)
Project builded
Added Error when trying to get service that not exists (silexphp/Pimple behavior)
Fixes bug #3 "pimple and requirejs" which throws a ReferenceError in browser environment

Uncaught ReferenceError: module is not defined pimple.js:128