Move padding to anchors in navigation

With the padding on the <li>, the nav item appears clickable when it
really isn't. This makes the entire box clickable.
Use pry-rails to auto-wire rails c
Reduce duplication between threads and research

* Extract shared code into a parent controller
* Assign creator to current_user in `create_resource` hook
* Remove `respond_to :html` since it is added for us by
  inherited_resources
* Fix indentation in some places
Combine index views for research and posts
Share posts/new between posts and research