[WIP] Adopted template overriding from other actions like update

Currently when you use the `SyliusResourceBundle` standalone, when you want to override the template for the delete action you have to define it this way:

``` yaml
my_delete:
    pattern: /my/{id}
    methods: [DELETE]
    defaults:
        _controller: my.controller.my:deleteAction
        template: MyCoreBundle:My:delete.html.twig
```

This is inconsistent with the other actions. This PR changes this so that it works with the folloging syntax:

``` yaml
my_delete:
    pattern: /my/{id}
    methods: [DELETE]
    defaults:
        _controller: my.controller.my:deleteAction
        _sylius:
            template: MyCoreBundle:My:delete.html.twig
```

Before merging this PR we should reconfigure the routes so that `SyliusWebBundle:Backend/Misc:delete.html.twig` will be used again ;-)
Configured template for all delete actions
Change the way how Doctrine fixtures bundle is initialized & polish README file
Moved backorders enabled to parameters.yml
Refresh cart right after cart_change event
Make the product changes logged
Make the short description versioned as well
Merge pull request #793 from Sylius/products-loggable

Make the product changes logged
Fix problems with specs failing about missing dependencies
Handle deleted items properly in backend
Fix order number generation
Merge pull request #795 from stloyd/bugfix/specs

Fix problems with specs failing about missing dependencies
Add softdeleteable for customers
Merge pull request #796 from Sylius/deleted-items

Handle deleted items properly in backend
Add product mapping for taxon model
[WebBundle] Remove some useless characters from template

Fix #798.
Implement basic state resolver and shipping states for order
Set the currency on the order properly
Set the currency for orders in Behat scenarios
Merge pull request #797 from foopang/products-by-taxons

Add product mapping for taxon model