Layouts, grids and panels

Layouts
* Makes widget inherit from element
* Adds layout which also inherits from element
* Adds grid and panel layouts
* Uses grid layout in meta dialog

Other changes
* Corrects issues with several of the stand-alone files by fixing and using makeStaticLoader.php

Change-Id: I6b92c0204e176c914c26eff8c03ea417578e080c
Merge "Layouts, grids and panels"