Customize: Hide Controls link is itself hidden in IE

[westonruter]

As discovered in #32296:

I will note in IE that, with and without the patch, the Hide Controls link is… hidden. This seems to be due to the z-index: -1 introduced in r39214 for #38762.

Screenshots in ​https://cloudup.com/cdo2nHseiyD

[westonruter]

via @timmydcrawford in https://core.trac.wordpress.org/attachment/ticket/32296/32296-e.diff

[westonruter]

In 40507.0.diff​ via @timmydcrawford:

I have added a proposed fix for that. I opted to change the order of the elements in the DOM to allow the background on .devices to stack naturally... also had to add a position attribute to that class get the background/fade to function properly which resulted in adding the wrapper div.

You can see the screenshots above of this diff in IE9 with a normal English translation, and a longer string.

[westonruter]

In 40510:

Customize: Fix visibility of "Hide Controls" link in IE.

Amends [39214].
Props timmydcrawford.
See #32296, #38762.
Fixes #40507.

[westonruter]

Re-opening for consideration in 4.7.5

[desrosj]

@westonruter anything left keeping this from being closed out?