Various world generation changes

- Do not call reset on builders explictly. That is up to the
  implementation to decide
- Do not enforce Vanilla flat layers to be on all flat configs

Signed-off-by: Chris Sanders <zidane@spongepowered.org>

src/main/java/org/spongepowered/api/world/generation/config/FlatGeneratorConfig.java

@@ -36,8 +36,12 @@ import java.util.Optional;
 
 public interface FlatGeneratorConfig extends ChunkGeneratorConfig {
 
+    static FlatGeneratorConfig standard() {
+        return Sponge.game().factoryProvider().provide(Factory.class).standard();
+    }
+
     static Builder builder() {
-        return Sponge.game().builderProvider().provide(Builder.class).reset();
+        return Sponge.game().builderProvider().provide(Builder.class);
     }
 
     List<LayerConfig> layers();
@@ -68,4 +72,9 @@ public interface FlatGeneratorConfig extends ChunkGeneratorConfig {
 
         Builder populateLakes(boolean populateLakes);
     }
+
+    interface Factory {
+
+        FlatGeneratorConfig standard();
+    }
 }

src/main/java/org/spongepowered/api/world/generation/config/NoiseGeneratorConfig.java

@@ -57,7 +57,7 @@ public interface NoiseGeneratorConfig extends ChunkGeneratorConfig {
     }
 
     static Builder builder() {
-        return Sponge.game().builderProvider().provide(Builder.class).reset();
+        return Sponge.game().builderProvider().provide(Builder.class);
     }
 
     NoiseConfig noiseConfig();

src/main/java/org/spongepowered/api/world/generation/config/noise/NoiseConfig.java

@@ -42,7 +42,7 @@ public interface NoiseConfig {
     }
 
     static Builder builder() {
-        return Sponge.game().builderProvider().provide(Builder.class).reset();
+        return Sponge.game().builderProvider().provide(Builder.class);
     }
 
     int height();