FIXED: Cart price should be decimal storage
FIXED: All numeric data should be stored as decimal instead of double

Financial data should never be processed as a float because it can lead
to rounding errors and questionalble data integrity.
FIXED: Default numeric data does not require single quotes in the sql statement
ADDED: PayPal processing options to global config
FIXED: Test to make sure variable is present so PHP doesn't throw notice
CHANGED: Remove redeem coupon button for the time being

This can be re-instated later after the correct processing for the
button is in place.