Config system v1

Roughly inspired by what I've learned from my work on Space Station 14, without some of the unnecessary cruft and complexity.

Implementation is relatively simple once I figured out all the template order shenanigans.

src/dusk/settings.cpp

@@ -0,0 +1,28 @@
+#include "dusk/settings.hpp"
+#include "dusk/config.hpp"
+
+namespace dusk::settings::enhancements {
+    ConfigVar<bool> FastIronBoots("enhancements.fast_iron_boots", false);
+    ConfigVar<bool> InvertCameraXAxis("enhancements.invert_camera_x_axis", false);
+    ConfigVar<bool> QuickTransform("enhancements.quick_transform", false);
+    ConfigVar<bool> RestoreWiiGlitches("enhancements.restore_wii_glitches", false);
+    ConfigVar<bool> EnableBloom("enhancements.enable_bloom", true);
+    ConfigVar<bool> UseWaterProjectionOffset("enhancements.use_water_projection_offset", false);
+    ConfigVar<bool> MirrorMode("enhancements.mirror_mode", false);
+
+    void Register() {
+        Register(FastIronBoots);
+        Register(InvertCameraXAxis);
+        Register(QuickTransform);
+        Register(RestoreWiiGlitches);
+        Register(EnableBloom);
+        Register(UseWaterProjectionOffset);
+        Register(MirrorMode);
+    }
+}
+
+namespace dusk::settings {
+    void Register() {
+        enhancements::Register();
+    }
+}