Added round (portal) windows and tweaked UV mapping on triangle endpieces.

Fixed a texture issue with the 3m diagonal door 1 element.
Tweaked the small corner end triangles in the cornices folder (should be the right size to be useful now)
Added 4m element with three small windows.
Fixed the overhang on shallow roof 1x0.5m.
Changed chimney texture so the gaps are now visible (based on vanilla textures).

Fixed a materials issue meaning all lights were on all the time (took a while to catch due to this only appearing ingame, not in the building editor). The "wall" elements should now randomly be light or dark at night, except the continuous ones and ground floor doors. Foundation elements will be fixed in the near future - it's a lot of work!

Added 1m diagonal window 3 piece.
Fixed 2x3 diagonal shallow roof (no more overhang)
Added "custom" folder with some specific elements. So far, a large clock and a 14m octagonal roof for a forthcoming skyscraper.

Added missing mipmaps for tile textures.
Added graphical border to elements.
Added 1m wall with window 3.
Added 2m wall with window 4.
Added 2m diagonal wall with window 4.
Added new eave pieces. Reduced size of 2x1 (shallow) roofs to remove their overhang. Eaves should work with all sizes.