Parallels license versions enumeration.

typedef enum _PRL_VERSION_ENUM {
  PRL_VERSION_ANY = 0,
  PRL_VERSION_3X = 1,
  PRL_VERSION_4X = 2,
  PRL_VERSION_5X = 3,
  PRL_VERSION_6X = 4,
  PRL_VERSION_7X = 5
} PRL_VERSION_ENUM;