vcl::ITiledRenderable: add registerCallback()
vcl::ITiledRenderable: add registerCallback()

This can be overriden in applications, if they need a callback.

Change-Id: I0441e48afbbfd63a96d47c5cf837e6635ce72aff

JurassicWordExcel/core,JurassicWordExcel/core,JurassicWordExcel/core,JurassicWordExcel/core,JurassicWordExcel/core,JurassicWordExcel/core,JurassicWordExcel/core,JurassicWordExcel/core,JurassicWordExcel/core,JurassicWordExcel/core