Change to stats updates to greatly increase update speed

In order to speed the stats updates, we've suspended the updates for the project WU counts.  This does not affect WU counts or points, just the stats pages which tells donors how many WUs they have contributed to each project.

We have polled donors in the past regarding this issue, and there was overwhelming support for this change, especially if it could significantly increase stats updates speeds.  After doing some in house tests, we expect that this will greatly enhance stats updates speeds, so we have rolled this out.

Even if this is the main culprit for the slow stats updates, we may put this back in time, once we work out a better scheme for how to update this information and/or get hardware better suited for it.  The main issue here is that this is a lot of information, with data going back many, many years, and it has become unwieldy.

For now, this should lead to a pretty dramatic difference in stats update times.  It looks like we can now get it done in about 20 minutes, rather than the ~2 hours it was taking previously, for 3 hours worth of stats accumulated.  

If this looks good, we will likely switch stats updates to occur more frequently in the future, starting with every 2 hours.