Add post boxes on index and location index

Quick path for users to create a new ad, no matter where they enter the
site.

Add css for post photos

Add js for passing user from location selector to the location page, for
access to the new ad form.

Add css for admin sections of location and posts pages.

Fix jquery won't run unless you refresh page, caused by Turbolinks gem.

1- Install jquery-turbolinks gem:
gem jquery-turbolinks

2 - In application.js, require it immediately after requiring jquery:

//= require jquery
//= require jquery.turbolinks

3 - Restart server