Replace references to NEU with Firmament

src/main/kotlin/moe/nea/firmament/features/FeatureManager.kt

@@ -0,0 +1,53 @@
+package moe.nea.firmament.features
+
+import kotlinx.serialization.Serializable
+import kotlinx.serialization.serializer
+import moe.nea.firmament.Firmament
+import moe.nea.firmament.features.fishing.FishingWarning
+import moe.nea.firmament.features.world.FairySouls
+import moe.nea.firmament.util.data.DataHolder
+
+object FeatureManager : DataHolder<FeatureManager.Config>(serializer(), "features", ::Config) {
+    @Serializable
+    data class Config(
+        val enabledFeatures: MutableMap<String, Boolean> = mutableMapOf()
+    )
+
+    private val features = mutableMapOf<String, NEUFeature>()
+
+    private var hasAutoloaded = false
+
+    init {
+        autoload()
+    }
+
+    fun autoload() {
+        synchronized(this) {
+            if (hasAutoloaded) return
+            loadFeature(FairySouls)
+            loadFeature(FishingWarning)
+            hasAutoloaded = true
+        }
+    }
+
+    fun loadFeature(feature: NEUFeature) {
+        synchronized(features) {
+            if (feature.identifier in features) {
+                Firmament.logger.error("Double registering feature ${feature.identifier}. Ignoring second instance $feature")
+                return
+            }
+            features[feature.identifier] = feature
+            feature.onLoad()
+        }
+    }
+
+    fun isEnabled(identifier: String): Boolean? =
+        data.enabledFeatures[identifier]
+
+
+    fun setEnabled(identifier: String, value: Boolean) {
+        data.enabledFeatures[identifier] = value
+        markDirty()
+    }
+
+}