Merge pull request #73 from mlosch/master

Implemented have seen map.
get the entire path and integrate tsp
return entire path and integrate tsp
add tsp trait
Merge pull request #74 from Wlan1991/master

tsp with entire path
Merge pull request #75 from mlosch/master

Small changes
Revert "Merge pull request #74 from Wlan1991/master"

This reverts commit 64a0595eff4cc14e8afb30e6fa6f50d54ea01485, reversing
changes made to 558edb21d095c54b6979f76b0aba1de83f2833da.
put back tsp changes
add missing return statement. Also catch div by 0 errors.