Hide view

Like the test case below, it's common to use multiple instances of `Quilt.Show` on the same element.  This causes a bug as each element just adds or removes the `hide` class.  By using `hide-<cid>` in combination with the style rule `[class*=hide-view]` we can correct this issue without tracking multiple views explicitly.

I'm especially interested in opinions from @parkerault and @mponizil.  :smiley: