Merge pull request #6 from OlegYarosh/new_documentation

New documentation
Updated API methods for like and comment photos. Implementing them to site.
Merge branch 'live' of github.com:OlegYarosh/pin into live
Modified profile photo modal styles
Changes in database schema gor user background comments and likes. API methods for user background likes and comments add and get. Popup modal window on profile page with comments and likes
Improved documentation of the project, refs #309
Changed the way environment variables are accessed in settings, to see if it will help to build readthedocs