users who specify "0.3" as the recipe format in their recipe, get an error saying it is not available. ... and then the list of possible options *does* include it:
gwenhwyvar:/tmp% bzr dailydeb bzr-svn.recipe
bzr: ERROR: deb-version not fully expanded: {latest-tag}. Valid substitutions are: ['{time}', '{date}', '{revno:package}', '{revno}', '{svn-revno:package}', '{svn-revno}', '{git-commit:package}', '{git-commit}', '{latest-tag:package}', '{latest-tag}', '{debversion:package}', '{debversion}', '{debupstream-base:package}', '{debupstream-base}', '{debupstream:package}', '{debupstream}', '{revdate:package}', '{revdate}', '{revtime:package}', '{revtime}']
bzr-builder should mention if the user is not using the latest version, and should only list the subsitutions available in the *current* version.
