Remove permission "Add Order"

I tried to figure out what the permission `ftw.shop: Add Order` does (because I wanted to change the lawgiver action group mapping) – but I couldn't find out.

My grep says:

```shell
projects/packages/ftw.shop[master]% git grep 'ftw.shop: Add Order'                                                                                                  jone4tw.local
ftw/shop/__init__.py:setDefaultRoles("ftw.shop: Add Order", ('Manager',))
ftw/shop/configure.zcml:     title="ftw.shop: Add Order"
ftw/shop/lawgiver.zcml:        permissions="ftw.shop: Add Order"
ftw/shop/profiles/default/rolemap.xml:    <permission name="ftw.shop: Add Order" acquire="False">
ftw/shop/tests/test_setup.py:                self.failUnless('ftw.shop: Add Order' in selected_permissions)
```

The `__init__.py`, `configure.zcml`, `lawgiver.zcml` and `rolemap.xml` are permission setups and `test_setup.py` tests some parts of those.
But it seems not to be used at all !?

@lukasgraf can we remove this?