Show Builder Support

CHANGES:
* Added show builder support for doctrine, doctrine_odm and propel.
* A simple template for show builder added.
* Show action which can be used as an object action in list builder.
* Minor Italian translation modifications and Turkish language support.

Show builder template requires improvements. Even though this type of pages require higher levels of customisation in comparison to list builder, it can be nice to have a good looking boilerplate template.