[xml-fold addon] Add findEnclosingTag utility
Remove unused variable
[xml-fold addon] Remove another unused var
[vim keymap] Style tweaks

* simpler concat
* less escaping
* shave a line
* throw early
* throw new error
* single quotes
* format returns
* rm unneeded parens
* add whitespace
* re-add braces
[show-hint addon] Restructure

Also makes sure that no two hinting dialogs can be active at the
same time.

Issue #1619
[merge addon] Initial add
[show-hint addon] Fix problem with close event firing too late
[markdown mode] Fix bug with two links or email addresses on same line.
[test harness] Escape < and & in test input/results.
Document inputRead and keyHandled events
Mark release 3.14.0
Bump version number post-3.14
[merge addon] Fix layout on Firefox

Work around percentage width rounding problems.
[tern addon] Work-in-progress
[xml-fold addon] Prevent infinite recursion from weird lastIndexOf behavior

Issue #1625
Support insertAt option to addLineWidget

Issue #1627
[vim keymap] Fix bugs in line handling

Closes #1612
Fix bug in addLineWidget / insertAt implementation

(f674dd148c27c882d3a85885caa9c27bb5638ee5)
[matchtags addon] Add

Issue #1625
[real-world uses] Add Echoplexus and Shadertoy