-- Details -- 
This Game Script controls industry and town growth by requiring
industries to be served for new ones to be build. 
Overall global economy index depend on percentage of towns and industries served
have impact on new industry creation and town growth thresholds.
Passengers and mail must to be delivered to towns in order for them to
grow. In case of medium towns (>5 k inh.), also good or food cargo must to be delivered,
large towns (>10 k inh.) require fuel and building materials.
The amounts of passengers and mail or good and food or petrol and building materials 
to deliver for towns to grow, and the industry serving requirments for enabling natural 
industry building can be changed with parameters.

-- Requirements --
OpenTTD 1.4 or greater. Tested with OpenTTD 1.7 and 1.7.1.

-- Parameter details --
- Towns -
1. Passengers + mail transport percentage required: [0 - 99]
This defines the mininum percentage of both passengers and mail
that must be transported in a town in order for it to grow. Set
to above 0 to enable the town growth control in the game script.

2. Goods+food transport percentange required: [0 - 100]
Mininum percentage of both good and food cargo
that must be transported in a medium town in order for it to grow.

- Industries -
3. Fuel+building materials transport percentange required: [0 - 100]
Mininum percentage of both petrol and building materials cargo
that must be transported in a large town in order for it to grow.
Set to 0 if you doesn't have grf supporting these cargoes.

4. Percent of industries required to be served: [0 - 99]
In order for new industries to be opened naturally, this
percentage of industries must be served.

5. Percent of cargo to transport from an industry: [1 - 99]
In order for an industry to be considered served, this percentage
of the cargo production must be transported from it.

6. Points threshold needed to change global economy mood: [0 - 99]
Difficulty setting, low value gives more permissive economy system.
Economy index depend on this threshold, game year and number of town and industries served.

7. Economy index threshold indicating global wealth: [5 - 50]
Difficulty setting, if economy index is below this value 
and industries service requirement is not fulfilled, no new industry would appear.
If economy index is negative and beyond this threshold, town growth would be limited.

8. Industry: Try to keep the number of industries on map: 
Will build new industries in case of closure, if economy index is positive.
