reduces number of db queries
O(1) QUERIES FOR VALIDATE ITEMS
Merge branch 'development' into even_better_validations
removed renewal change and added benchmarking test
num_available o(1) query
set rservation source to correct variable
fast availables
move helper methods to reservation model
tighten scopes for better memory footprint
typo
fine tuning
make comments clearer
organize validations file much better
merge development
forgot a qmark
Merge pull request #680 from YaleSTC/even_better_validations

reduces number of db queries in cart validations
Revert "reduces number of db queries in cart validations"
Merge pull request #685 from YaleSTC/revert-680-even_better_validations

Revert "reduces number of db queries in cart validations"
use += instead of <<
Revert "Revert "reduces number of db queries in cart validations""

This reverts commit c0c89af0aa724aa89af45d1d3609c7ce8c75d5aa.