use breadcrumb once implemented in knp menu

[dbu]

once breadcrumb is merged in knp menu, we should look at how we do breadcrumbs and document it for users. see
KnpLabs/KnpMenu#45

[dantleech]

The referenced PR seems rather dead. I guess this is still a issue for the future?

[lsmith77]

KnpLabs/KnpMenu#161 seems to be addressing this for 2.1

[wouterj]

Removed 2.0 milestone as I don't think breadcrumb renderers are going to make it in KnpMenu 2.1

[dbu]

agreed. and its not a blocker to have it.