Feature/map generator

[bacox]

Hi all,

It took me a bit more time to fix the biggest problems after showing the initial generator in #1557 .
Here is the pr but keep in mind it is still a work in progress.
There is enough that can be improved/fixed.
The code that I added in core/random and map/random really could some improvement.

However, sharing the code gives you the opportunity to give feedback as well :)

The generator has the following options:

• Select map size
• Change climate
• Set seed for deterministic map generation.
• Select generator algorithm.
• Edit win criteria
• Set initial funds.

After generation there are two options: Open in the editor to further change the scenario, or start game to directly play the scenario.

Option to change climate:

Large map with river generator:

Scenario after using the start game option:

Most of the added lines of code are in the ui of the map generator window.
The river generator uses a combination of perlin noise for the trees, rocks, and meadows, as well a random walk for the river. The river algorithm creates a path for the river and is widened using a somewhat random kernel that move over the path of the river.

Known problems:

• The ocean and lakes algorithm is there as well but do not work well.
• The entry and exit points can be buggy and need some more work.
• The path between the entry and exit points carves through the water and destroys the river.
• The win-criteria is pure random and not based on any of the map features.
• The available building, resources, and empire map is currently ignored.
  I'll keep working on improvements.

I'm looking forward to any feedback :)