Clean links - remove superfluous tracking elements from URLs

[dethos]

For the last couple of months I've been running a modified version of Redlib on my personal “instance.” I essentially added a new option to the settings that make Redlib remove common tracking elements from the links posted to Reddit. A small privacy gain when we don't have browser extensions to do this job.

Since it is running smoothly, I think this could benefit all Redlib users. So here's the PR; feel free to dismiss or suggest improvements.