sqlite vs. xml metadata

[Anders F Björklund]

I updated the "sqlite" branch, which adds a "database"
parameter to the yum metadata (type: rpm-md) channels.

http://createrepo.baseurl.org/
http://en.opensuse.org/Standards/Rpm_Metadata

When set, it will load the metadata from an sqlite
database instead of parsing it from the xml markup.
If there is no .sqlite.bz2 upstream, it will convert
the .xml.gz repodata to .xml.sqlite locally* instead.

* needs the "sqlitecachec" python module installed
   http://packages.ubuntu.com/python-sqlitecachec

The cache is about a third (or so) when the extra info
is stored in the database instead of in the cache...
That is: it's on par with the rpm channels or the apt
channels, especially if including changelogs/filepaths.

See https://code.launchpad.net/~afb/smart/sqlite
and https://bugs.launchpad.net/smart/+bug/244889

--anders