aeron-io#197: added no-op onGroupHeader() method to AbstractTokenListener

Author: csoroiu

main/java/uk/co/real_logic/sbe/otf/AbstractTokenListener.java

@@ -64,6 +64,11 @@ public void onEndComposite(final Token fieldToken, final List<Token> tokens, fin
  // no op
  }
 
+ public void onGroupHeader(Token token, int numInGroup)
+ {
+ // no op
+ }
+
  public void onBeginGroup(final Token token, final int groupIndex, final int numInGroup)
  {
  // no op