tag: add enhanced support for {{merge*}} tags

* Rationales can be posted on the article talk page.
* Multiple articles can be tagged at once with the appropriate merge
tag.
warn: show red usage message on {{uw-coi-username}}

This is in addition to that shown on {{uw-username}}.
Per request at WT:TW.
protect: move unprotection to top of preset list for admins

Just so it's always accessible.
warn: add {{uw-copyright-new}}, thanks to Ankit-Maity

issue #128
warn: change prompt message upon self-warning

Per discussion at WT:TW.
warn: add uw-af series of warning templates

Per request at WT:TW.
warn: add uw-unsourced4

Let's hope the line endings are not stuffed.
warn: add three AFT-related single-issue notices
warn: group warnings into categories; add and remove some warnings

- Level 1-4im warnings are now in optgroups.
- uw-redirectX, uw-afX, uw-icsX have all been removed
- uw-disruptive1-3 has been added
warn: remove mainheaderRe, it is actually unused
Revert "warn: group warnings into categories; add and remove some warnings"

This reverts commit 7ef43b8da3b12cfe50de4f9c2ac81206c13ab392.

Conflicts:
	modules/twinklewarn.js
Re-add disruptive warning templates that were removed
Replicate rv 544846566 by Amorymeltzer: Change 'e-mail' to 'email', for consistency
Slight comment copyedit
Rename templates
warn: remove uw-disruptive4, as it is a redirect to uw-generic4
warn: space fixes; hide article name in summary of generic block notices

Previously the edit summaries were like: "You have been blocked from editing on [[xyz]]." Well, no, you've been blocked from all articles. So it was misleading.
warn: (take 2) group warnings into categories; add and remove some warnings

- Level 1-4im warnings are now in optgroups.
- uw-redirectX, uw-afX, uw-icsX have all been removed
- This time I'm using jQuery data rather than expando properties, to
lower the chances of failure. However, I think the real cause of failure
was the jQuery code that assigned to |selectedEl|, so I have modified
that. Hopefully it doesn't fail this time!