Expose transition durations on plugin constructors; closes #13656
Remove `layout: nil`.

It throws a warning with the latest Jekyll.
Run `grunt`.
Fix #14076: Add unit test for tooltips on SVG elements

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Merge pull request #14299 from twbs/fix-14076

Add unit test for tooltips on SVG elements
Merge pull request #14061 from hnrch02/fix-13656

Expose transition durations on plugin constructors; closes #13656
Firefox 31 has been released, so rm pre-v31 browser bug entry