overhauling proxy_url
overhauling proxy_url

- Decode possible HTML entities in the input URL
- Add the safe extension for the shortpath as well
- Formatting
- Documentation

friendica/friendica,annando/friendica,fabrixxm/friendica,fabrixxm/friendica,annando/friendica,tobiasd/friendica,tobiasd/friendica,fabrixxm/friendica,annando/friendica,tobiasd/friendica,tobiasd/friendica,annando/friendica,friendica/friendica,friendica/friendica,friendica/friendica,fabrixxm/friendica,friendica/friendica,fabrixxm/friendica,annando/friendica,tobiasd/friendica