Make News Less Intrusive

The original version polls for new news podcasts after every song and
plays them if they haven't been played before.  This could leave you
getting the 1pm news at 2:13, then the 2pm news at 2:14.

Now, news only plays if it is from the current hour, and you are less
than 30 minutes into the hour.  This ensures at least 30 minutes of
music between each news segment, and prevents hearing the 2pm news at
3:10pm