fix bug https://github.com/AriaLyy/Aria/issues/543#issuecomment-559733124

fix bug https://github.com/AriaLyy/Aria/issues/542
fix bug https://github.com/AriaLyy/Aria/issues/547
修复下载失败时，中断重试无效的问题
增加忽略权限检查的api，`ignoreCheckPermissions()`

M3U8Component/src/main/java/com/arialyy/aria/m3u8/BaseM3U8Loader.java

@@ -15,6 +15,7 @@
  */
 package com.arialyy.aria.m3u8;
 
+import android.text.TextUtils;
 import com.arialyy.aria.core.common.RecordHandler;
 import com.arialyy.aria.core.download.DTaskWrapper;
 import com.arialyy.aria.core.download.DownloadEntity;
@@ -59,6 +60,9 @@ public abstract class BaseM3U8Loader extends AbsLoader {
 
   protected String getCacheDir() {
     String cacheDir = mM3U8Option.getCacheDir();
+    if (TextUtils.isEmpty(cacheDir)) {
+      cacheDir = FileUtil.getTsCacheDir(getEntity().getFilePath(), mM3U8Option.getBandWidth());
+    }
     if (!new File(cacheDir).exists()) {
       FileUtil.createDir(cacheDir);
     }

M3U8Component/src/main/java/com/arialyy/aria/m3u8/M3U8RecordAdapter.java

@@ -131,7 +131,8 @@ public class M3U8RecordAdapter extends AbsRecordHandlerAdapter {
 
   @Override public int initTaskThreadNum() {
     if (getWrapper().getRequestType() == ITaskWrapper.M3U8_VOD) {
-      return mOption.getUrls().size();
+      return
+          mOption.getUrls() == null || mOption.getUrls().isEmpty() ? 1 : mOption.getUrls().size();
     }
     if (getWrapper().getRequestType() == ITaskWrapper.M3U8_LIVE) {
       return 1;