Centralize the templates used for administration forms.
Review Request #7851 — Created Jan. 7, 2016 and submitted
We had a number of templates that were piggy-backing on the logic in the siteconfig/settings.html template, but this wasn't a very good organizational approach. These templates weren't related to siteconfig settings, and there was a theoretical possibility that a siteconfig-related change would break the other templates. We now have a base template, djblets_forms/admin/change_form_page.html, which can be relied upon as a base template for any forms that are to appear in the administration UI. It contains the same logic as the original form, with the additions of including the js18n library, defining the jQuery object, and allowing the save message to be configured. Other templates have been updated to use this as the new base, and backwards-compatibility templates have been added. There's also a fix for the margin at the bottom of the extension form, which was placed on the wrong element, causing a visual issue.
Tested the extension configuration, site settings, and upcoming
integration pages. I was able to save each without problems.