factory catalyst goods

[poppo]

Hi!

I want to add "catalyst" goods.

• Factories can work without supply of catalyst goods
  
• Catalyst goods boost factories produce (like electricity,passenger and mail)
  

I suggest three patterns to add catalyst goods:

• add new desc type "factory_catalyst_desc_t", which has same flag as factory_supplier_desc_t and boost ratio.
  
• when factory_supplier_desc_t's consumption==0, we treat it as catalyst. (but we need boost ratio and consumption ratio for catalyst)
  
• we add "catalyst number", which supplier goods number is larger than catalyst number, these goods are treated as catalyst. (but we need boost ratio)
  

Here, I paste the patch with version 1 (add factory_catalyst_desc_t)factory_catalyst.patch.

[prissi]

I think this is a very interesting change. However, I am currently on holiday and not really have time to review and test such big changes.

Moreover, one needs also discuss how and when the factory builder builds those catalysts. Otherwise they will never appear other than if they are part of another chain.

Maybe like the distribution wieght for normal factories, or just with less retrys?