Add settings for each individual customizations that panopoly_admin makes to the node edit form

Over the years, many people have complained about the individual customizations that panopoly_admin makes to the node_edit form. Unfortunately, they can only disable the whole panopoly_admin module and get rid of them all, even if it's only one thing they'd like to disable.

I propose adding settings for each customization so that site builders can pick and choose what they want or don't want!

There's a couple existing issues for some of these:

• #2226625: Add Setting to Panopoly Admin to Disable Permalink Override
• #2446287: Uncombine "sticky" and "promote to front page" options