CHANGE-523: Discount Coupon updates and new features and clean up
Fix headers
CHANGE-598 - Clean up Product Price Manager 0 qty on Discount Quantity
ISSUE-23 - Clean up add to cart when non-numeric value is used and display message
CHANGE-481: Improve on lack of ability to create and manage multiple coupon codes
(Fix to sanitize newly-added params)
CHANGE-481: Remove extraneous debug code
ISSUE-23 - Clean up add to cart when non-numeric value is used and display message
additional clean up
TESTFRAMEWORK - add basic travis.yml file. Still needs work to config environment variables and phpunit stuff
ISSUE-24 - Change in LOGIN_EXPIRY_NOTICE to reflect actual timeout setting for admin (SESSION_TIMEOUT_ADMIN).
Merge pull request #27 from zencart/v160

V160