Display where traderoutes go

[IRampagingRhin0]

There has been a few cases of traderoutes going through planets, but never connecting

Not sure the best way to go about this, possibly a way to hover over a planet and change the connected traderoute lines colour for a more visual representation of where they actually link up to

[Slornie]

Also ref #51

[andrewfullard]

Resolved by #100