What version are you running?
3.0.15
What's the URL of the page this enhancement relates to, if any?
Posting comment to review request
Describe the enhancement and the motivation for it.
Most times developers just copy+paste link from a review request to another review request. It's quite ugly to see this full URL and if someone changes the URL of the current Review Board instance the URL is not clickable anymore.
So it would be helpful if Review Board could automatically identify own review board URL and strip that down like github for the issues und pull requests.
Example:

A developer paste the URL https://rb.company.de/r/52113/ to a comment and Review Board looks into ALLOWED_HOSTS settings to identify that the URL is the current Review Board instance. After the developer click "ok" Review Board strips the URL down to /r/52113/ format to use internal linking.
What operating system are you using? What browser?
Linux, Firefox
Please provide any additional information below.