Consistent default variable value for revisioning_require_update_to_publish

Problem/Motivation

The revisioning_require_update_to_publish variable uses different default value throughout the site causing confusion. It is defaulted to TRUE on the setting page, making one think it is enabled. It is then defaulted to FALSE when actually checking permissions.

Proposed resolution

The default should be TRUE for all references. A user without update permissions to an entity should not be able to change the published status (update) of that entity.

Remaining tasks

Patch attached, reviews needed.