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
For this part I think it is too complitcated because I would have to also modify ```_create()``` so it call ```create()``` with the right arguments, and I would have to rewrite entirely ``` _run()``` so it call ```_create()``` with the right arguments. I am not sure it worth it.