Header Stats

I've started working on generating stats for individual headers within
messages. Rather than take up too much space here on the list for the
results, I am keeping the results in my github fork [1] of the
compression-test code and will be posting summaries of the results
periodically on my personal blog [2]. I will be putting together a summary
of my findings together in time for the interim meeting next week.
Unfortunately, however, I will not be able to attend the meeting.

[1] https://github.com/jasnell/compression-test/blob/master/counts/
[2] http://chmod777self.blogspot.com/2013/01/http-20-header-stats.html

- James