Added backend support for Comments.

- Single Vote per comment checks and balances added. 
 - Fixed up RsGxsImage stuff. (TODO move to proper REF counted Image).
 - Added GxsTokenQueue ticks were required.
 - Made GenExchange publicToken() fns  public, so that comments can use them.
 - Added OwnVote details to Comments 



git-svn-id: http://svn.code.sf.net/p/retroshare/code/trunk@6224 b45a01b8-16f6-495d-af2f-9b41ad6348cc

libretroshare/src/services/p3posted.cc

@@ -108,6 +108,9 @@ void	p3Posted::service_tick()
 {
 	dummy_tick();
 	RsTickEvent::tick_events();
+
+	mCommentService->comment_tick();
+
 	return;
 }