Protection against non per-vertex colours
Rendered hex geometry in a batch object belonging to the world
Switched back to solid fills per tile
Separated hex fill/edge/centre batch building into separate functions
Introduced functions to optionally remove fill/edge/centre vertex lists from batch
Initial construction of hex features now checks ui states first
Added emergency deletion of existing vertex_lists if a new one is generated prematurely (needs revisiting)
Added ui callbacks to toggle geometry inclusion in batch for different hex features
Started batch rendering of region borders
Currently bugged renderning