Enhance ValidationUtils by some location validation

[danielfeismann]

Summarizing dicussions it would be great to extend the ValidationUtils by some validation of the loctions.

Thinks that should be validated (may incomplete list, please add points if you see them)

• Nodes should be close together (distance to be defined) at
  • switches
  • transformer
• Start and end coordinate of line string should have the same coordinates as the node a and node b of that line