Link with city flag and industry generation

[MagicBuzz]

Hello,

Whatever the settings I use, my map always ends up with a big number of industries that are useless to link together.

I hate funding industries (I prefer the challenge of linking random industries) but normal algorythm build too much industries and with too few realism.

I'm thinking about two things :

1/ An option to allow building secondary industries (game start and game random) only in cities.
I don't know how "secondary" industries is managed in the game core code and GRF code, but if possible, I think this could address partially the problem.

2/ Add some NewGRF flags/variables to have a better link between the cities and the industries.
By exemple for industry types :
- Allow in town (Multiple/One/City/No City) : this would force the "unicity" of an industry type in town whatever the user setting, and force/avoid industry type in cities/no cities
- %age of towns : by exemple, with a "20" setting, only 1 town for 5 would have this industry type. This would allow to limit some industries while allowing other to spawn many times

What about it?

[2TallTyler]

This is NewGRF territory, not changes to the vanilla industries. I’ve addressed these issues (and more) in Improved Town Industries: https://github.com/2TallTyler/improved_town_industries