Fix clicking every link when changing conversation
Refactor javascript code

  - Created jquery.notify.js
  - Created jquery.at-bottom.js
  - Remove jquery.hammer.minjs

  TODO:
  - Add doubletap action for autocomplete in input field
  - Clearing new notifications while in the same conversation does not
    currently work.
Add link to Firefox plugin

  Newer versions of Firefox support native desktop notifications, the
  link to the plugin is for older versions, < v22.