[Suggestion] check before building resource sink ships

[YorrickVander]

Far too often players cannot build ships as a required ship yard npc is stuck at X% because the resource sink ship being built ran out of something halfway through. In the early game this is very hard work as it can block the player from building construction ships to fix the missing ware production or build defence/mining/trade ships to shore up the gaps. Covers 3.20 and 3.50b2 builds.

[Santi]

Totally agree with YorrickVander, plenty of reports of people not being able to build ships because of this. It is quadruple frustrating because you have to travel to the shipyard to build your ship (wasted trip), then you cannot because of lack of wares (find out what is missing), then you have to provide the wares (wait for one of your ships to become free or cancel their planned trips), then you have to hang around till the ship finish so you can slot your ship before the shipyard decides to build another (making building a ship an over 1 hour process with luck).