ScriptInfo: add setter for appendReturnValue

This matches the getter isReturnValueAppended. It will
be useful when we externalize the parameter parsing logic.

Author: ctrueden

src/main/java/org/scijava/script/ScriptInfo.java

@@ -256,6 +256,11 @@ public boolean isReturnValueAppended() {
 		return appendReturnValue;
 	}
 
+	/** Gets whether the return value is appended as an additional output. */
+	public void setReturnValueAppended(final boolean appendReturnValue) {
+		this.appendReturnValue = appendReturnValue;
+	}
+
 	// -- AbstractModuleInfo methods --
 
 	/**