New diagram as a subway map

[supermuka]

Would be really nice we have a diagram as a subway map like this:

https://www.pads.rwth-aachen.de/global/show_picture.asp?id=aaaaaaaabswgyrs&w=842&q=77

Elements similar UML Activity diagram

Requirements:

• Activity element
• Relationship element
• Decision element
• Start/End element
• Interation with elements (mouse click)
• Create new relationship when interate on diagram, creating new relationship between activities