Added new searchCustomer method. My old method worked fine on small data sets. When you have over 30,000 customers, it starts to get unhappy. Adding over 100,000 checkins also did not sit well with it.

Added benchmark.php, build-checkins-table.php (Adds lots of checkins), and updated checkinapp.js to use new search method. Also fixed something with index.php
Added benchmark.php. Use at your own risk.