Log Message:
Update to 0.18:

0.18 release.  performance improvements, features, and bug fixes.
This release is dedicated to Shweta Narayan.

- most operations sped up by a factor of 2 or better; many sped up
  by up several orders of magnitude.
	- special thanks to Matt Johnston <matt@ucc.asn.au>, Derek
	  Scherger <derek@echologic.com>, Linus Torvalds
	  <torvalds@osdl.org>.
- new concept: "database vars".  Used in several features below.
- new features:
	- new file "MT/log" can be edited while you work,
	  sets default changelog.  (no change in behaviour if
	  you do not edit it.)  Thanks to Jeremy Cowgar
	  <jeremy@cowgar.com>.
	- monotone now stores default netsync
	  server/collection, initialized on first use of
	  netsync.
	- you no longer need to manually import server
	  keys, monotone will fetch the key from the server on
	  first netsync.
	- monotone keeps track of keys of servers you have
	  previously synced with, to prevent man-in-the-middle
	  attacks.
	- several powerful new "automate" commands added.
	- new command 'ls known', lists files that are under version
	  control.  Thanks to Florian Weimer <fw@deneb.enyo.de>.
	- preliminary "inodeprints" functionality -- speeds up diff,
	  status, etc.  No UI or documentation yet -- in a working
	  copy, 'touch MT/inodeprints' to enable, then commit or
	  update to populate cache.
- UI improvements:
	- Added short options -r, -b, -k, -m.
	- default to 'dot' ticker-style when stderr is
	  not a tty, thanks to Derek Scherger
	  <derek@echologic.com>.
	- New "-@/--xargs" option, helpful when using new
	  automate commands.  Thanks to Richard Levitte
	  <richard@levitte.org>.
	- New "--depth" argument to 'log'.  Thanks to Richard
	  Levitte <richard@levitte.org>.
	- 'db info' gives statistics on space usage.
	- new command 'dropkey'.  Thanks to Jeremey Cowgar
	  <jeremy@cowgar.com>.
- robustness improvement: if monotone crashes in a working
  directory and --dump and --debug were not specified, saves
  debug dump to "MT/debug" for analysis, instead of
  discarding.
- new contributed scripts: CIA (cia.navi.cx) notification,
  email notification, Bash completion.
- 33 new integration tests.  total line coverage: ~82%.
- many bug fixes
	- Special thanks to Matt Johnston <matt@ucc.asn.au>,
	  for going above and beyond to track down the last
	  release blocker.

- upgrading from 0.17 requires only a 'db migrate'.