Features/Goals for Yum 4.X

• API break
• New repodata format: dev/NewRepoDataIdeas
• Delta-able repodata
• x509 Certs/sigs for repo and pkg verification
• separate-process downloader - multiple-files-at-a-time downloader
• depsolver changes? (need specifics)
• Detached package signatures
• yum plugins be able to register objects available to api callers of yum. Ie: yum.plugins.pluginname.method() being available from callers
• deal w/plugin type_INTERACTIVE for guis vs for clis