- Bump the minimum libvirt version from 1.2.2 to 1.2.12, because
virDomainDefineXMLFlags wasn't introduced until that version.
- Use the correct format for the generated file notice, so that golint
ignores the generated files.
- Add a yacc-based parser and a hand-written lexer to read the
remote_protocol.x file from libvirt's sources.
- Use the new parser to generate the constants used to communicate with
libvirt.