Workboard - Make the edit icons on the columns actually work

Summary: Made the edit path of the Edit controller work (before only create worked), also added in the link for the cog icon to actually land you on the edit page for the correct column. Some cleanup too. *cough*

Test Plan:
Click on gear
Look at fancy title you are about to edit
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Reviewers: epriestley, #blessed_reviewers

Reviewed By: epriestley

CC: Korvin, epriestley, aran

Differential Revision: https://secure.phabricator.com/D7933
Fix InvalidArgumentException PHUIFormPageView::pageErrors

Summary: Argument 1 passed to PHUIObjectBoxView::setFormErrors() must be of
the type array, not null.

See: <https://github.com/facebook/phabricator/pull/482>

Reviewed by: epriestley