7.0 export partner and address

Completion of the magentoerpconnect_export_partner module to fix the export of partners and add the export of addresses.

This PR depend of this one and need to be merged after : 

* [ ] https://github.com/OCA/connector-magento/pull/33

Initial proposal on lauchpad : 
https://code.launchpad.net/~akretion-team/openerp-connector-magento/7.0-export-partner-and-address/+merge/224180
Well, there is one last point I don't get : in _export_dependency, in order to export there is a condition : 
```
rel_binder = self.get_binder_for_model(binding_model)
if rel_binder.to_backend(binding_id) is None:
```
In my tests, after creating the bindings for my addresses, it does not pass this condition, and so, it won't export my addresses.
I just don't get what this is... not what should I do in order to make it pass the condition