Clean up of RSS feeds

The number of registered RSS feeds are slightly below 150 chemistry oriented blogs; a number of them have ceased to exist, or moved to a different host, or simply changed URL. I just spent an hour or so, debugging these changes, as the Cb software does not really report that. But things are now updated again.

Updated CMLRSS feed

After some questions from Jean-Claude, I worked a bit on the CMLRSS feed. It now links to a page with blog items for that specific molecule. When doing that, I also noted that it was not listing the right molecules, so fixed that too; it now again shows the molecules most recently blogged about.