Game settings screen, and minor fix on discordRPC

- Uses BG previously from the input config screen, which has gotten a new BG
- Minor tweak on the input config screen to display all inputs names regardless of if they are bound or not
- Added Mod1 function to `funcs.lua`, may be useful again sometime
- Added game settings
  * Manual locking (per gamemode, per ruleset, on harddrop or on softdrop)
  * Piece colours (per ruleset, TTC or Arika)
  * World Reverse toggle
- Moved the discordRPC `libs/` directory, as it's a third party library
- Edited the `discordRPC.lua` file to look for the dll at the right place regardless of how you run the game (until we fuse it that is)

This should have probably been done in several commits, sorry about that

scene/game_config.lua

@@ -0,0 +1,78 @@
+local ConfigScene = Scene:extend()
+
+ConfigScene.title = "Game Settings"
+
+require 'load.save'
+
+ConfigScene.options = {
+    -- this serves as reference to what the options' values mean i guess?
+    {"manlock",      "Manual locking", {"Per gamemode","Per ruleset","Harddrop", "Softdrop"}},
+    {"piece_colour", "Piece Colours",  {"Per ruleset", "Arika",      "TTC"}},
+    {"world_reverse", "World Reverse", {"No",          "Yes"}},
+}
+local optioncount = #ConfigScene.options
+
+function ConfigScene:new()
+	-- load current config
+	self.config = config.input
+	self.highlight = 1
+
+	presence.details = "In menus"
+	presence.state = "Changing game config"
+	discordRPC.updatePresence(presence)
+end
+
+function ConfigScene:update()
+end
+
+function ConfigScene:render()
+	love.graphics.setColor(1, 1, 1, 1)
+	love.graphics.draw(
+		backgrounds["game_config"],
+		0, 0, 0,
+		0.5, 0.5
+	)
+    
+	love.graphics.setFont(font_3x5_4)
+    love.graphics.print("GAME SETTINGS", 80, 40)
+    
+	love.graphics.setColor(1, 1, 1, 0.5)
+    love.graphics.rectangle("fill", 20, 98 + self.highlight * 20, 170, 22)
+    
+	love.graphics.setFont(font_3x5_2)
+	for i, option in ipairs(ConfigScene.options) do
+        love.graphics.setColor(1, 1, 1, 1)
+        love.graphics.printf(option[2], 40, 100 + i * 20, 150, "left")
+        for j, setting in ipairs(option[3]) do
+            love.graphics.setColor(1, 1, 1, config.gamesettings[option[1]] == j and 1 or 0.5)
+            love.graphics.printf(setting, 100 + 110 * j, 100 + i * 20, 100, "center")
+        end
+	end
+end
+
+function ConfigScene:onKeyPress(e)
+	if e.scancode == "return" and e.isRepeat == false then
+		playSE("mode_decide")
+		saveConfig()
+		scene = TitleScene()
+	elseif (e.scancode == config.input["up"] or e.scancode == "up") and e.isRepeat == false then
+		playSE("cursor")
+		self.highlight = Mod1(self.highlight-1, optioncount)
+	elseif (e.scancode == config.input["down"] or e.scancode == "down") and e.isRepeat == false then
+		playSE("cursor")
+		self.highlight = Mod1(self.highlight+1, optioncount)
+	elseif (e.scancode == config.input["left"] or e.scancode == "left") and e.isRepeat == false then
+		playSE("cursor_lr")
+        local option = ConfigScene.options[self.highlight]
+        config.gamesettings[option[1]] = Mod1(config.gamesettings[option[1]]-1, #option[3])
+	elseif (e.scancode == config.input["right"] or e.scancode == "right") and e.isRepeat == false then
+		playSE("cursor_lr")
+        local option = ConfigScene.options[self.highlight]
+        config.gamesettings[option[1]] = Mod1(config.gamesettings[option[1]]+1, #option[3])
+    elseif e.scancode == "escape" then
+        loadSave()
+        scene = TitleScene()
+	end
+end
+
+return ConfigScene