Release version 0.2.9.
Bumping to v0.3.0 for development.
Added version_comparison_key to MunkiInstallsItemsCreator processor
Fail if version_comparison_key exists and said key is missing from installs item.
Support version_comparison_key per-installs-item for MunkiInstallsItemsCreator
MunkiImporter: support for setting 'version_comparison_key'

- when calling makepkginfo, MunkiImporter may generate a single
  installs item, so the support for setting this key need not
  be as sophisticated as supporting dicts as in
  c9c42d8dcfbe40a83acb017bc57785c784c16d7c
Update CHANGELOG.md
Updated documentation for input variables.
Initial support for searching, new github module package
Style fixes for PkgCopier description
Copier: Handle error case of glob not matching any path
Cleanup
GitHubSession: init a None token, only add auth header if one is set
Don't use a token by default, add --use-token option

- search rate limit in practice is 6-7 per minute, which is probably plenty.
Handle over-rate-limit 403 message
More error handling, including urllib2.URLError
Set new stored token to 0600 permissions
setup_token() TODOs
Simplify --file-contents handling, commented-out text-match results handling
Display user in heading rather than hardcoded 'autopkg'