More strict HTTP calls and better error handling

[holm]

I had to make quite a few changes to better handle errors. I switched to use the requests package instead of direct use of urllib, as it is much easier to work with.

I'm not sure you want this as there are quite a lot of changes, but thought you should have the option.

[jmg]

Hey! i'm really glad you want to contribute to the project. I was seeing the changes and it all look great. I'll check it better and will make the marge definitely.