Added popup functionality and Library

* doPopup() JavaScript call creates a centered popup div with user
    defined width, height, title, content, and calls an optional
    callback function

* Library with currently non-modifiable book list, and a popup with the
    books' details

Signed-off-by: Gergely Polonkai <polesz@w00d5t0ck.info>

composer.json

@@ -26,6 +26,7 @@
         "jms/di-extra-bundle": "1.0.*",
 	"doctrine/doctrine-migrations-bundle": "dev-master",
         "egeloen/ckeditor-bundle": "dev-master",
+	"friendsofsymfony/jsrouting-bundle": "dev-master",
         "gergelypolonkai/tcpdfbundle": "dev-master"
     },
     "scripts": {