Fix an exception when trying to access ungenerated chunks in an area that has no region file

BlueMapCLI/src/main/java/de/bluecolored/bluemap/cli/BlueMapCLI.java

@@ -223,7 +223,7 @@ public class BlueMapCLI {
 		File resourcePackFolder = configFolder.toPath().resolve("resourcepacks").toFile();
 		resourcePackFolder.mkdirs();
 		File[] resourcePacks = resourcePackFolder.listFiles();
-		Arrays.sort(resourcePacks);
+		Arrays.sort(resourcePacks); //load resource packs in alphabetical order so you can reorder them by renaming
 		
 		List<File> resources = new ArrayList<>(resourcePacks.length + 1);
 		resources.add(defaultResourceFile);

BlueMapCore/src/main/java/de/bluecolored/bluemap/core/mca/MCAWorld.java

@@ -28,6 +28,7 @@ import java.io.BufferedInputStream;
 import java.io.DataInputStream;
 import java.io.File;
 import java.io.FileInputStream;
+import java.io.FileNotFoundException;
 import java.io.IOException;
 import java.io.RandomAccessFile;
 import java.nio.file.Path;
@@ -225,6 +226,8 @@ public class MCAWorld implements World {
 				throw new IOException("invalid data tag: " + (tag == null ? "null" : tag.getClass().getName()));
 			}
 			
+		} catch (FileNotFoundException ex) {
+			return Chunk.empty(this, chunkPos);
 		}
 	}
 	

BlueMapSponge/src/main/java/de/bluecolored/bluemap/sponge/SpongePlugin.java

@@ -166,7 +166,7 @@ public class SpongePlugin {
 		File resourcePackFolder = getConfigPath().resolve("resourcepacks").toFile();
 		resourcePackFolder.mkdirs();
 		File[] resourcePacks = resourcePackFolder.listFiles();
-		Arrays.sort(resourcePacks);
+		Arrays.sort(resourcePacks); //load resource packs in alphabetical order so you can reorder them by renaming
 		
 		List<File> resources = new ArrayList<>(resourcePacks.length + 1);
 		resources.add(defaultResourceFile);