Updated with license, invalid, & paid statuses.

Per official BitPay API docs: A BitPay.com invoice can be in one of the following states: “new”, “paid”, “confirmed”, “complete”, “expired” or
“invalid”.
Updated with version validation info.
Updated to check first if osc func already defined

Last require() updated could cause a fatal function redeclaration error if it's already defined.  Also added license information.
Updated with license information.
Updated with minor formatting and license info.
Updated with license information.
Merge pull request #9 from ionux/master

Bug fix for func redef error and added other statuses & license info