Trading tweaks

[Legion]

Suggestion to make trading a good money maker past like your first week:

Set interstellar trading missions to use 10-15% of your total cargo space instead of a flat amount. This lets you take 30%-45% of your cargo space each trip which can actually be a good haul no matter what stage of the game you're in.

Unrelated suggestion, make trading an option when you hail a ship, to allow direct trading of resources, modules, and ships.