Provide convenience method addTextCrumb() to PhabricatorCrumbsView

Summary: We currently have a lot of calls to `addCrumb(id(new PhabricatorCrumbView())->...)` which can be expressed much more simply with a convenience method. Nearly all crumbs are only textual.

Test Plan:
  - This was mostly automated, then I cleaned up a few unusual sites manually.
  - Bunch of grep / randomly clicking around.

Reviewers: btrahan, chad

Reviewed By: btrahan

CC: hach-que, aran

Differential Revision: https://secure.phabricator.com/D7787