WordPress-Plugin v3.1.0

Misc refactoring & security improvements, updated docs.

What's Changed

• Added nonce and user permission check by @xecdev in #55
• Added paybutton prefix to generic option names by @xecdev in #56
• Escaped variables properly when echo'ed by @xecdev in #57
• Refactored Session usage with cookies by @xecdev in #58
• docs: external services by @lissavxo in #60
• Updated README by @xecdev in #61

New Contributors

• @lissavxo made their first contribution in #60

Full Changelog: 3.0.0...3.1.0