update dependencies

* Pimple moved to https://github.com/silexphp/Pimple
* kriswallsmith/assetic is now 1.2.0 (was 1.1.2 before)
* symfony/dom-crawler is now 2.5.7 (was 2.5.4 before)
* symfony/process is now 2.5.7 (was 2.5.4 before)
* willdurand/negotiation is now 1.3.4 (was 1.3.3 before)
completed changelog for v1.0.1
sync changelog with commits since the v1.0.1 tag
only activate existing navigation items