Adds new routes for tables, visualizations and tags
Adds tag navigation. Adds History pushState so we can get rid of the hashtags in the URL
Fixes path
Merge branch 'develop' of github.com:CartoDB/cartodb20 into develop

* 'develop' of github.com:CartoDB/cartodb20:
  changed visualization to use backend impl
  Don't add more layers to a map if they would go over the layer consistency limit
  Implement Map#admits_layer?
  Temporarily return privacy as uppercase
  cdb 2.1 fixed
  fixed interactivity on the first time
  Reorganize smoke spec tests
  comment configuration fields
  Implement Layer#base_layer? and Layer#data_layer?