add ability to customize how detail fields are rendered

[joshuadavidthomas]

Adds a detail_field_renderers attribute to CRUDView that is a dictionary of fields to callables that return strings. Allows for customizing the rendering of certain fields in the detail view without having to resort to a custom object_detail.html template just for one field.

[joshuadavidthomas]

@jefftriplett Not sure on this one, but I find myself wanting to tweak how a certain field is rendered in the template frequently and find it annoying to have to create a whole custom template and/or templatetag just for that one field.

Going this route initially as a instead of my initial thought of "List view fields can have widgets through the django_tables2.columns.Column and form view fields can have widgets through form widgets, what if detail view fields also had widgets??"

[jefftriplett]

Does overriding the neapolitan.py template make it work better with default templates, or does it create confusion when people start looking for what is going on, or why a new project without this template tag doesn't work?

[joshuadavidthomas]

Good point. I kept it this way to ease the transition, but don't necessarily care about keeping the templatetag module named the same. I'd rather go for clarity.