Indicate pre-selected multi-value item

Issue #32 

Last selected item has a checkmark next to it and when a new item is selected the background goes gray. Once the user goes back to the home tableview of the debug menu the checkmark will update to the new selection and will display accordingly the next time they open the multi-value item tableview
Oooh ok. Yeah that makes sense. I thought that the Values array was always going to be an array of integers that acted as the corresponding indices of the items in the Titles array. Thanks for the help!