Miscellaneous

[RaceTheMaSe]

This PR contains:

• some typos fixed
• NPE in FeatureElevationLayer without existing profile
• usage info about getSignedDistance2D calculating in 3D
• SRS create flipped logic - please check if I am not mistaken
• check duplicate vertices in TileMesher - if two features have equal edges the meshing becomes errourous when processed by the TerrainConstraintLayer