v0.18 - Event images, mod loader

Major changes:

• Event images are added! These are currently disabled by default, but can be enabled in the options menu. I find that while playing online, there’s a bit of lag in loading the images, so they’re disabled by default for now, but they should look better in one of the downloaded versions.
• Mod loader: This uses the target mod’s game.json file, and the base game’s music and images. See the “Mods” button in the options menu.
• Curated mod list: If you want to add a mod, send a pull request adding a line to mod_list.tsv at https://github.com/aucchen/social_democracy_mods
• New event: Exodus from the Reichsbanner (high militarization leads to Center and DDP exit from the Reichsbanner).
• New achievement: Klassenkampf (high worker support, low middle-class support)

Minor changes:

• UI change for the options menu
• various tweaks to effects and thresholds
• Wirth is an option for chancellor after the death of Müller if Joseph Joos is the Zentrum leader.
• Defunding the Reichswehr increases coup progress more, and increases paramilitary strength.

Backend changes:

• a bunch of dendrynexus updates for event images (called face-image in the code).

Future changes:

• more fiscal policy, welfare, and labor policy options
• Preparing for a Steam release?