Update SpecRunner to get tests passing.
Use CSS content to show placeholders

- Remove the use of .text() to show placeholders, and instead make use
  of the after pseudo element and content tags in css to show a
  placeholder.

  This has the advantage of when a user clicks the placeholder, the user
can immediately type instead of having to reclick. The downside is this
puts the onus of placeholder into the markup/css layer. Now placeholders
are determined by a "data-inline-placeholder-text" attribute on the
contenteditable element and accompanying css to make it use of it.