This: c7ac6802b1b8258c4f1cdcd61d3f80b6cf477fc6 (part of the mapsharing I think) changed that. Btw. your branch is based on an old version (but does not matter for the tileset data anyway).
The commit above changed the path that are used in the other tilesets. 0.A uses requires the gfx/ prefix, everything after c7ac6802b1b8258c4f1cdcd61d3f80b6cf477fc6 does not.