Notable changes :
* extensions lists were originally UL/LI but I replaced them with Alert neutral, collapsed by default
* the "Get extensions from iTop Hub..." button was located between both fieldset. I moved it on top of the page, just below page title
- Optimize TWIG templates includes (don't pass context to autonomous components)
- Preliminary work of the top bar and breadcrumbs features
- Removal of images dedicated to the breadcrumbs feature
- bootstrap.inc.php is now included by approot.inc.php
- remove all unescessaries includes of bootstrap.inc.php
- in bootstrap.inc.php autoload can be bypassed using a feature flag because "why not"