Fix of wrongly uploaded git files.

* Fixed crash when modifying lower level length when altitude equals to or greater than 100%, or higher level length when altitude is 0%

* Fixed crash when lower length equals to 50% and shorter
* Fixed error of position calculate for non crossing layout with grouped tracks
* Fixed error of position and length calculate for side retaining walls for lower level
* Fixed missing upper fences on side of transition B
* Fixed terrain alignment error on some solid transition section.

* Colission bugfix on crossing layout
* Retaining wall form bugfix on crossing layout
* Terrain alignement on lower level improved

* Added option to have curves on transitions
* Added common axis for general slope

* Added option to adjust transition length
* Improved slope option
* Improved menu

Fixed crashes with small angles

Added some extra radius

Hotfix for snapping to exisiting tracks

Update of mod preview image.