added entities menu, link, pages, routes, article tab

vipra-ui/app/html/articles/show.html

vipra-ui/app/html/directives/article-link.html

vipra-ui/app/html/directives/entity-link.html

vipra-ui/app/html/directives/entity-menu.html

vipra-ui/app/html/entities/articles.html

vipra-ui/app/html/entities/index.html

vipra-ui/app/html/entities/show.html

vipra-ui/app/html/entities/topics.html

vipra-ui/app/html/explorer.html

vipra-ui/app/html/index.html

vipra-ui/app/html/topics/index.html

vipra-ui/app/js/app.js

vipra-ui/app/js/controllers.js

vipra-ui/app/js/directives.js

vipra-ui/app/less/app.less

vipra-ui/gulpfile.js