[B3.1] Canyon Editor: 2-2-1 placement, new virage suggestion

[TMarc]

When I try to place the virage block 2-2-1 inside a canyon, although there should be enough place for the road itself,
it is not possible:



I would suggest to allow placement of such blocks in such conditions,
and also to have a curve which makes 3 or even 4 blocks.