Added improved hydra scaling

[SimonFlapse]

Change log
Added min, max and trigger to config
Added online_player_scale to config

Made hail hydra chances a variable of:

• number of online players (toggle)
• evolution based on a custom formula that has a slow scaling until evolution 0.8

Current config is in need of balancing, what is shown is just an example to illustrate the changes.

What is this?
These changes would make hail hydra better suit all kinds of maps with increased customization.

What is new?
We can now customize:

• Hydras minimum chance
• Hydras maximum chance
• Toggle whether player count should affect these chances
• Amount of players needed for configured chances to be true.
  • Above this number further increase the chances
  • Below this number decrease the chances
  • Each player increases or decreases the chance with 1%

What have been removed
Evolution_scale didn't do much towards customizing the spawn chances. The equivalent in these changes are:
{min = 0.2, max = min + evolution_scale}

Technical changes
The formula for calculating the chance is:
(0.00003*(E*100)^3 + 0.004 * (E*100)^2 + 0.3 * (E*100))*0.01 where E = force.evolution_factor

Approx values shown in evolution = (percentage of max):
| 0.25 evolution = 10% | 0.50 evolution = 29% | 0.60 evolution = 45% | 0.75 evolution = 58% |
| 0.80 evolution = 65% | 0.90 evolution = 81% | 1.00 evolution = 100% |

Yet to do

• Create public functions to change these settings runtime
• Implement compatibility with the old config using the conversion in What have been removed
• Balance the default configuration
• Ensure current maps aren't broken from these changes
• Set max to -1 in config if it's unused
• Make overriding the online_player_scale for a single hydra spawn possible

[linaori]

What's max = 0?

[SimonFlapse]

What's max = 0?

It's if you don't want the chance to change. I just didn't want to remove max = ? for clarity
max <= min <=> max = min

[linaori]

That sounds odd, perhaps -1 would be a good alternative?

[SimonFlapse]

We could do -1 in the default settings, but I might actually set a maximum setting.
It doesn't matter if it's 0, -1 or anything less than min.

[linaori]

It doesn't matter if it's 0, -1 or anything less than min.

It's the way it's treated, when I see max being lower than min, my brain will wtf for a moment, where as -1 indicates that it is disabled (indexof being a prime example). Additionally could also use "false" instead to turn it off, or a different key.

[mheguy]

As this is still WIP, going to tag this as post-0.17

[SimonFlapse]

What a nice surprise. No RB for me...

[SimonFlapse]

Has been used in Diggy launched 2019-03-01 and Quadrants 2019-03-02