Added editition of extra fields in n_n_relations

[luiscoms]

I idded a new feature whrited on Forum http://www.grocerycrud.com/forums/topic/1552-edit-extra-fields-in-n-n-relations/

[mirhmousavi]

+1

[khoyot3]

+1

[luiscoms]

This woks on grocery crud 1.4.1 version

[luiscoms]

I just rebased the branch to unclude this improvement

[brunomrpx]

Great feature, I need this

[lfelipecunha]

:+1:

[marcosdalte]

:+1: when this feature will be available?

[matheusfontana]

:+1:

[williamborba]

:+1:

[YHartonuk]

Sorry, how can be used callback_edit_field functionality for extra fields?

[luiscoms]

Hi @YHartonuk, I do not use grocery crud anymore, this merge was not accepted on time.