Composition grids overlay in VFB2.0 and viewports

There is currently no proper way to display composition assist grids. There is an imagecomphelper script, but it only works in one active viewport, this complicates setting up the angle if you use another viewport to move the camera itself (the grid will disappear from the camera viewport and will appear in the active one).

It would be nice to have a tool from Corona that allows you to enable composition grids both in the framebuffer (variety of classic options such as golden ratio / thirds / spiral etc. and perhaps uploading your own .PNGs , similar to what was described in the Stencil Feature request) and in the camera's viewport.

In the second case, the interface can be added to the settings of the camera itself and grid will be displayed in the corresponding camera viewport only.