Change back-to-notes to containing a link
Add basic styling to back-to-notes
Prevent link from doing the default action
Add space in between event and selector

This was a small bug that fired a click event if any of post-container was
clicked, rather than just back-to-notes
Simplify post template

No need to have a div surrounding the link, just give the class
back-to-notes to it directly.
Add new mixin for general link style
Switch style to using new mixin
Merge branch 'style/back-button'
Switch to using togglePreview method

It might be less explicit, but the intent of clicking .back-to-notes if to
switch views. So the only way to get that behavior — trigger the even
listener for the model — is to change the is_preview bool.
Merge branch 'use-togglePreview'