Comment 4 for bug 758753

Some further clarification over this; for these group-* icons the paths are hardcoded to read from a specific location. It is not the change from .svg files to .pngs but the change in pathname. The pathname and the icon location require simultaneously changing. To avoid a half-and-half situation this requires adding "Breaks:" to the meta-data in the .deb to ensure a smooth upgrade.

The solution at this stage therefore has to rely of not changing the pathnames. One possible solution is to embed the .pngs into .svg files (this uses a url:// and base64 encoding). The files will be approximately 25% larger from the base64 encoding. I'll look in to confirming if this is possible.