Introducing Diskuto - an embeddable comment system

[Sönke Ludwig via Digitalmars-d-announce]

Improvements implemented by now:

- Authorization and time limit (5min client facing, 15min server facing) 
is now enforced for editing and deleting comments
- The page must be queried first before any action is allowed (prevents 
trivial command line batch "attacks", as well as trivial spam automation)
- The main comment form is minimized by default (only the text area, 
single-line height)
- Maximum height of comments limited (will show scroll bars if exceeded)
- Temporal boosting limited to hours instead of days
- E-mail and website length limited
- Message contents don't overflow the content area
- Displayed comment count corrected

Some changes may require Ctrl+F5 to refresh the cache.

Thanks to everyone who helped testing the boundaries so far! This 
definitely sped up the initial finalization phase by a large margin. 
There are still some open points, but this gets close to being a 
complete product:

- Implement moderation (!) and user registration to avoid identity 
spoofing (pluggable source user database)
- Additional heuristics to prevent batch operations from a single 
client, possibly just showing a CAPTCHA for IPs that show a high 
frequency of operations on the same topic(s)
- Work out how to best limit the visual or functional nesting level of 
comments
- Translations to more languages