Fixed a lot of bugs

HMCLAPI/src/main/java/org/jackhuang/hellominecraft/util/UpdateChecker.java

@@ -44,7 +44,6 @@ public final class UpdateChecker implements IUpdateChecker {
         return new OverridableSwingWorker() {
             @Override
             protected void work() throws Exception {
-
                 if (value == null) {
                     versionString = NetUtils.get("http://huangyuhui.duapp.com/info.php?type=" + type);
                     value = VersionNumber.check(versionString);

HMCLAPI/src/main/java/org/jackhuang/hellominecraft/util/tasks/download/FileDownloadTask.java

@@ -177,6 +177,8 @@ public class FileDownloadTask extends Task implements PreviousResult<File>, Prev
                         lastTime = now;
                     }
                 }
+                if (downloaded != contentLength)
+                    throw new IllegalStateException("Unexptected file size: " + downloaded + ", expected: " + contentLength);
                 closeFiles();
                 if (aborted)
                     tempFile.delete();