box pieces having a 45 degree cut for the corners looks very nice, and
works well, but the cut interferes with the extended piece options, so
this reuses the pieces to take ones with the 45 degree lip cut off,
which would be combined with the flush extended pieces, much like how
things used to work for these pieces before I made the box pieces use
said cut.
this also commits a demo of combining everything extended-style
phew
Signed-off-by: Brian S. Stephan <bss@incorporeal.org>