Minor changes at Coloradolib

Most of the posts at Coloradolib are what I call "link plus snark." But I make occasional attempts at analysis and reportage. Starting now, these posts will be labeled "punditry" and "frontlines," respectively. I added the appropriate links to my sidebar. While I was at it, I added Haley's Comment, Ave Cassandra, Denver Ozone and Coyote Gulch to my blogroll. And changed my archiving system from weekly to monthly.