Revert "Use <label>s rather than placeholders"

isso/js/app/text/postbox.jade

@@ -9,19 +9,13 @@ div(class='isso-postbox')
                         div(class='text')
         section(class='auth-section')
             p(class='input-wrapper')
-                label(for='isso-postbox__author')
-                    = i18n('postbox-author')
-                input(type='text' id='isso-postbox__author' name='author'
+                input(type='text' name='author' placeholder=i18n('postbox-author')
                       value=author !== null ? '#{author}' : '')
             p(class='input-wrapper')
-                label(for='isso-postbox__email')
-                    = i18n('postbox-email')
-                input(type='email' id='isso-postbox__email' name='email'
+                input(type='email' name='email' placeholder=i18n('postbox-email')
                       value=email != null ? '#{email}' : '')
             p(class='input-wrapper')
-                label(for='isso-postbox__website')
-                    = i18n('postbox-website')
-                input(type='text' id='isso-postbox__website' name='website'
+                input(type='text' name='website' placeholder=i18n('postbox-website')
                       value=website != null ? '#{website}' : '')
             p(class='post-action')
                 input(type='submit' value=i18n('postbox-submit'))