the set of features and fixes

[oklas]

Hello,

this is the set of

• make authorized domain checking optional
• add remark about that authorized domain is optional
• add error processing
• process port carefully with url analizing

[eslachance]

If you want to maintain this 6 year old code that I haven't touched in that long, you're welcome to Fork this repository as your own, and maintain it. I can link to it from the readme.