add like button in user interface

htdocs/_templates/_master.php

htdocs/_templates/login.php

htdocs/js/app.min.js

htdocs/js/app.min.js.map

htdocs/js/app.o.js

htdocs/libs/api/auth/login.php

htdocs/libs/api/auth/signup.php

htdocs/libs/api/posts/like.php

htdocs/libs/includes/User.class.php

htdocs/libs/includes/UserSession.class.php

project/grunt/dist/app.js

project/grunt/dist/app.js.map

project/grunt/dist/style.css

project/js/templates/index.js