#14 Fails with large numbers of caches

[Brian Erickson]

This is from user feedback.

"When I exported to a .gpx file and tried to import to CacheMagnet, it imported about 9,500 of them before choking out a memory error... and ran very slowly."

People routinely use GSAK to hold large databases of caches (20,000+). This will need to be addressed if they are to use CacheMagnet in the same way.

CacheMagnet should either perform better with large numbers of caches or limit the number to something it can handle.