[WIP] TreeBrowserBundle refactoring

This PR refactors the TreeBrowserBundle to make it more generic. All parameters needed to control the javascript tree are taken from the tree. As a side effect, this will (hopefully) properly implement, moving and reordering of nodes, allow for custom icons and valid_children.

Once merged there can be many different trees in the application and we can easily build a pure phpcr browser (or you could build a server side filesystem browser, which is my refactoring test case ...).

This is work in progress, especially the PhpcrOdmTree is not adapted to that yet.
additional check for route being set
adjust select.js and use JsonResponse
fix tests and integrate tree-bundle
include proper css and allow to cancel operation via event
Merge pull request #17 from uwej711/tree_refactoring

TreeBrowserBundle refactoring