Arthur: Changed growth triangles from images to CSS. Patch by Tyrael.

Signed-off-by: Martin Stone <martin@d7415.co.uk>
Arthur: Changed alignment of new CSS arrows.

Signed-off-by: Martin Stone <martin@d7415.co.uk>
Added "imaplog.txt" to .gitignore.

Signed-off-by: Martin Stone <martin@d7415.co.uk>
Arthur: Removed now-unused rank images.

Signed-off-by: Martin Stone <martin@d7415.co.uk>