[TYPO3-mvc] use relation type RELATION_BELONGS_TO_MANY for fields with MM relation and maxitems=1

[Franz Koch]

Hey Xavier,

> I did not dig into this issue but a comment on your patch:
>
> - chunk starting at 181: please use if
> (isset($columnConfiguration['MM'])) { instead of without the isset

thanks - fixed it locally. As I think there might be maybe also be some 
other issues (I was half asleep when doing this), I'm reviewing it again 
myself when my brain started working again today and wait for other 
comments before I provide a updated patch.

-- 
kind regards,
Franz Koch