[Dropdown] Add back closeOnClick functionality for dropdowns.

[tjhiggins]

Use this functionality heavily on our site.
Unsure why it was excluded in 6 so I disabled by default.

Shamelessly copied this commented out code from DropdownMenu. Then retooled to fit the new flow.

Do I also have to rebuild foundation.js in this pr?

[tjhiggins]

Looks like this breaks anything with data-close in dropdown. Going to fix and repush.

[tjhiggins]

Updated. Solution is a little heavy handed, but powerful. Suggestions?

[zurbchris]

seems like it would be much faster and less code to say:

if(_this.$element.find(e.target).length){
  return;
}
_this.close();
$body.off...

for the check if the click was in the dd or not. Otherwise, I think this is a fine feature.

[tjhiggins]

@zurbchris Updated

[tjhiggins]

Found another bug with my addBodyHandler, and a unused settings var in dropdown.scss

[zurbchris]

This is a pretty good feature. I've added it to the 6.1 Milestone list, and there will be a new 6.1 specific branch shortly if you could change this pr to that branch. Don't worry about compiling a new copy of the js, we'll take care of it.

[tjhiggins]

@zurbchris #7478
Should I delete this pr?

[zurbchris]

I'll take it in case the new dropdown isn't complete in time. I do like the feature :)

[rafibomb]

@tjhiggins Thanks!