Exclude partner field from merchant account form in the dashboard

[roadsideseb]

Creating a merchant account in the dashboard allows to select a partner although each Amazon merchant account is equivalent to a new partner. As a result, we shouldn't allow for picking a partner but create a new partner for the merchant account.

[natea]

Yeah, this confused me too. When I created a new Merchant account, and then went to the Partners page, there was a partner called "Amazon Amazon.com (US)"

[roadsideseb]

I've added a helptext in acb5ed0 that should make it a bit clearer. I've also change it so that the partner name (when auto-generated) is the same as the name of the MerchantAccount. Do you think that makes sense or is it clearer to remove the partner completely from the form and do a get_or_create on the partner? I'm a bit worried about side effects when partners already exist and not being able to change a wrong partner in the dashboard. I'd appreciate your thoughts.