Easy Digital Downloads - Conditional Success Redirects 1.1.8

Fix: A PHP warning was logged if there were no items in the cart.
Dev: Refactor how plugin is loaded.
Dev: Refactor how licensing is instantiated.
Dev: Fix EDD_Conditional_Success_Redirects dynamically declaring properties.
Refactor: Update plugin author name to "Easy Digital Downloads".

Refactor: Update plugin author name to "Sandhills Development, LLC."
Dev: Compatibility with EDD 3.0.

Fix: Redirect loop if EDD core success page URL matches the redirect URL