Add download --auto argument, emulating autoDownloadPurge = true in the CLI.

To be used when caching dependencies in CI workflows.

src/main/java/rife/bld/BaseProject.java

@@ -534,7 +534,22 @@ public class BaseProject extends BuildExecutor {
     @BuildCommand(help = DownloadHelp.class)
     public void download()
     throws Exception {
-        downloadOperation().executeOnce(() -> downloadOperation().fromProject(this));
+        var auto = false;
+        var arguments = this.arguments();
+        while (!arguments.isEmpty()) {
+            var argument = arguments.get(0);
+            if (DownloadOperation.AUTO_OPTION.equals(argument)) {
+                arguments.remove(0);
+                auto = true;
+            } else {
+                break;
+            }
+        }
+        if (auto) {
+            performAutoDownloadPurge();
+        } else {
+            downloadOperation().executeOnce(() -> downloadOperation().fromProject(this));
+        }
     }
 
     /**

src/main/java/rife/bld/help/DownloadHelp.java

@@ -5,7 +5,7 @@
 package rife.bld.help;
 
 import rife.bld.CommandHelp;
-import rife.tools.StringUtils;
+import rife.bld.operations.DownloadOperation;
 
 /**
  * Provides help for the download command.
@@ -15,13 +15,13 @@ import rife.tools.StringUtils;
  */
 public class DownloadHelp implements CommandHelp {
     public String getSummary() {
-        return "Downloads all dependencies of the project";
+        return "Downloads all dependencies of the project (take option)";
     }
 
     public String getDescription(String topic) {
-        return StringUtils.replace("""
-            Downloads all dependencies of the project
-                        
-            Usage : ${topic}""", "${topic}", topic);
+        return String.format("""
+                Downloads all dependencies of the project
+                
+                Usage : %s [%s]""", topic, DownloadOperation.AUTO_OPTION);
     }
-}
+}

src/main/java/rife/bld/operations/DownloadOperation.java

@@ -25,6 +25,7 @@ import static rife.bld.dependencies.Dependency.CLASSIFIER_SOURCES;
  * @since 1.5
  */
 public class DownloadOperation extends AbstractOperation<DownloadOperation> {
+    public static final String AUTO_OPTION = "--auto";
     private boolean offline_ = false;
     private HierarchicalProperties properties_ = null;
     private ArtifactRetriever retriever_ = null;