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
Ok, i'll change that.
I add the condition on the street to avoid to try exporting an adress for a partner if it does not have any address. (Would create a job in fail for nothing)
I think we can assume that if street is present, then the partner has an address (so we want to try creating one in magento), if it isn't present, it does not have any address and we do not even want to try creating an address on magento.
I put a condition on street, but it could have been on country_id or city...
What do you think?