More RSS tweaks

I added in Bob Schumaker’s lastmodified plugin to my blosxom setup. This adds automatically a Last-Modified header to everything that blosxom serves, in the header of the HTTP transaction. In addition, this plugin exports the variables so that other things can use them. I used that to add a lastBuildDate to my RSS format, which should help the aggregators figure out if they need to do anything. Let me say for the umpteenth time that I really dig blosxom.