Sets 10,000 as the default value of the App Engine search parameter...

..."number_found_accuracy" for searches from the VertNet portal, for the same reasons we now use this as the default for searches from the Web API.

I have tested this change to confirm that it will apply to searches through both the "simple" and "advanced" search interfaces in the portal.

However, it does _not_ apply to searches that include a sort (the API does not do this, either).  This is because "number_found_accuracy" was explicitly _not_ getting set for searches with a sort, and I am assuming there was a reason for that (there are no comments in the code to explain it).