The generated wrappers have an argument for every field in their "Args"
struct, and return everything in their "Ret" struct (these structs are
defined in the protocol file, and identified by procedure name).
Marshaling and unmarshaling is handled inside the generated procedures.
- 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.
