B56: no roads in the freeplay mod

[Luc-Alain Baumberger]

Hello,

I've just tested the new build, with a new freeplay.

However, instead of the build 55, in the build 56, there is no initial road.

[karolpawlowski]

I also observed this issue. Sometimes there is initial road, sometimes not, and sometimes there is only boundary sign without any road. Build 56

[dalerank]

fix #620. improved road create in freeplay mode. terrain generator refactoring.

→ <<cset ceffe2861d08>>