Lock attributes functionality.

- Add product attribute ho_import_profile and set the profile used to import the product.
- If an import has the <lock_attributes> option set all the attributes will be disabled on the product-page.
- Extra text is added to the attribute note: "Automatically filled by import %s".

- [x] Make it working for products
- [x] Make it working for categories
- [x] Make it working for customers (?)