#496. Added vouchers statistic.
#496 Display times redeemed count on pricing page
#496. Js vouchers stat added. Added voucher info delete on pass delele.
#496 fixed formatting of voucher code
#496 Improved comments
#496 Remove options on uninstall
Merge pull request #499 from laterpay/feature/496_track_vouchers_redeemed_count

Feature/496 track vouchers redeemed count
lgtm