adam: please tag and optimize your repository

Adam, I have uncovered the joys of creating a checkpoint in a darcs 
repository. The procedure is:
1) Create a tag: "darcs tag -m "my tag name"
2) Optimize with checkpoint option: "darcs optimize --checkpoint 
--compress" (will automatically check point at the last named tag.

Actually, 1 and 2 can be done as a single tag command with a 
--checkpoint option but I broke them apart for clarity.

This has a number of benefits:
1) Many operation are much faster
2) You can do a "darcs get --partial http://darcs.ibex.org/ibex" in 
order to pull a working darcs repository but *not* all the historical 
information. This is much faster and less bandwidth and disk intensive, 
and most people will not need this info.
3) Most importantly, "darcs push" and hence, "make propose-patch" 
generate e-mails with context *only* since the last checkpoint, 
eliminating the ridiculous verbosity of the current emails to [email protected]

-Tupshin