Fixed Sorts (Waitlist, Current Rentals, Overdue Rentals) + Added Edit Quantity Function for Racquet Inventory

//TODO: Added Edit quantity back end and basic crude front end stuff.
Plz make it pretty

HOW SORT WORKS!:

FRONT END: Have button's that a href to sort function in controller
with FIELD and CONDITION eg.
From Current Rentals:
 <br><a
href="/ctlCurrentRentals/ctlCurrentRentals/sort/Rental_ID/asc">(Asc)</a>

This passes into the SORT() function in ctlCurrentRentals the FIELD:
Rental_ID, and the condition ASC(ascending)

2. In the controller, within the SORT function:

IF( data to sort is not readily available via parent db and references
other databases like customer names) {
get whole array.
for each array, get necessary information .
Sort the array using sortArrayofObjectByProperty() method found in CORE)

ELSE (need to sort data that is already available in parent db like the
date) {
$this->databsename->sort($field,$condition)