type options = [ `bmake | `configure | `htdoc | `opt ]
type category = [ `apps | `base | `conf | `godi ]
type relop = [ `eq | `ge | `gt | `le | `lt ]
type dep = category * string * (relop * string) option
type confopt =
  Common.confopt = {
  name : string;
  default : string;
  description : string;
  implementation : [ `configarg of string | `makevar of string ];
}