Integrate recent changes in http-request demo
Integrate recent changes in http-request demo

* Make use of the new append syntax which allows appending of multiple
widgets.
* Change obsolete "createPage" method invokation to "create".
* Move layout-related code to the top

Change-Id: Ib48b5d4cd7c4d3aa5c6d57227288bf2d0c49023e

eclipsesource/tabris-js,moham3d/tabris-js,moham3d/tabris-js,softnep0531/tabrisjs,mkostikov/tabris-js,pimaxdev/tabris,eclipsesource/tabris-js,eclipsesource/tabris-js,mkostikov/tabris-js,pimaxdev/tabris,softnep0531/tabrisjs,paulvi/tabris-js