#1326 ongoing allowance of public index action call of viz endpoint
#1326
Merge branch 'master' into issue-1326

Conflicts:
	NEWS.md
Merge branch 'master' into issue-1326
#1326
Merge pull request #1549 from CartoDB/issue-1326

Visualizations endpoint should check if request is authenticated
Merge branch 'master' into 1561-json_visualizations_controller_fails_for_unlinked_tables