General cleanup and minor fixes (i.e. fixed the description message & made it show up on Special:Version).

As a side-note:
* NoC isn't the most intuitive variable name, although I do understand why it was chosen
* It'd be nice to see this code optimized a bit (i.e. using memcached instead of directly hitting the DB *always*) and merged back into the Comments extension; this seems like a useful feature which could easily be a part of the Comments extension ("extensions of extensions" are generally speaking a tad bit problematic, but not like it ever stopped the Semantic people...)