Improved search route

[svenseeberg]

Based on #84 we can include the speed of the SAR vessel and calculate the k-means for each time step. Based on the speed of the SAR vessel and the initial distance, the best route through time and space can be calculated.

[julled]

i am wondering if it makes sense to implement this, in this repo? i guess this is more something which i would expect from a proper MRCC software to calculate search patterns.
Anyhow its good to offer a path i think.