Add '$' to signature function pattern

closes #80

youtubeExtractor/src/main/java/at/huber/youtubeExtractor/YouTubeExtractor.java

@@ -88,7 +88,7 @@ public abstract class YouTubeExtractor extends AsyncTask<String, Void, SparseArr
  private static final Pattern patFunction = Pattern.compile("([{; =])([a-zA-Z$_][a-zA-Z0-9$]{0,2})\\(");
 
  private static final Pattern patDecryptionJsFile = Pattern.compile("jsbin\\\\/(player(_ias)?-(.+?).js)");
- private static final Pattern patSignatureDecFunction = Pattern.compile("(\\w+)\\s*=\\s*function\\((\\w+)\\).\\s*\\2=\\s*\\2\\.split\\(\"\"\\)\\s*;");
+ private static final Pattern patSignatureDecFunction = Pattern.compile("([\\w$]+)\\s*=\\s*function\\(([\\w$]+)\\).\\s*\\2=\\s*\\2\\.split\\(\"\"\\)\\s*;");
 
  private static final SparseArray<Format> FORMAT_MAP = new SparseArray<>();
 
@@ -299,7 +299,7 @@ private SparseArray<YtFile> getStreamUrls() throws IOException, InterruptedExcep
  }
  if (LOGGING)
  Log.d(LOG_TAG, "Get from youtube page");
- 
+
  getUrl = new URL("https://youtube.com/watch?v=" + videoID);
  urlConnection = (HttpURLConnection) getUrl.openConnection();
  urlConnection.setRequestProperty("User-Agent", USER_AGENT);