Export to JS the Customizer construct being deep-linked
Short-circuit embed() if panel/section/control already embedded
Add deferred.ready to Panel, Section, Control; embed when initialized
Focus on a panel/section/control when ready
Wait to autofocus on panel/section/control until element is embedded and preview has loaded.

Use an animation of 0 until the preview loads.
When focusing on panel/section/control, scroll into view
Use ?autofocus[section]=colors pattern for query param
Merge pull request #40 from xwpco/trac-28650

Trac 28650: Allow Customizer elements (controls, sections, and panels) to be deep-linked