default urlparse cache size to 20 instead of 2000.  The main use of
the cache seems to be to gain some speed in Grail, which is calling
urljoin with the same base for each anchor.  2000 is a bit too big for
Jeremy, who doesn't need the cache at all.  20 should keep at least
95% of the Grail speedup while wasting an insignificant amount of
memory in Jeremy's application.