Added additional header content types, removed functions inlace of native php code, #131.

Signed-off-by: Zane M. Kolnik <zanematthew@gmail.com>
Cart is now emptied after payment, #132.

Signed-off-by: Zane M. Kolnik <zanematthew@gmail.com>
Default license price notice, #113.

Signed-off-by: Zane M. Kolnik <zanematthew@gmail.com>
Change log updates.

Signed-off-by: Zane M. Kolnik <zanematthew@gmail.com>