Volume identity. Basic type.

 Every volume has a unique identity, a 32-bit word usually specified in the form
 v1.v2.v3.v4 where v1, v2, v3 and v4 are numbers in the interval 0-255.
 Dependent of the class of the volume, the numbers is choosen in separate
 intervals:

    RootVolume,SubVolume:       0.  1-254.  1-254.  1-254
    System ClassVolumes:        0.      0.    0-1.  1-254
    User ClassVolumes:          0.      0.  2-249.  1-254
    Manufacturer ClassVolumes:  0.      0.250-254.  1-254
    DirectoryVolume:          254.    254.    254.    253
    WorkbenchVolume:          254.    254.    254.    254
    Local WorkbenchVolume:    254.    254.    254.    252
    VolatileVolume:           254.    254.    254.  0-100

    Runtime:                1-253.       .       .

 In runtime 1-127 are used for system volumes
    1    pwrNode    Volume used by ProviewR.

 128-253 are used to create unique identities:
    128  Subid
    129  Dlid

 The string notation for a volumeid is _Vv1.v2.v3.v4, e.g. _V0.0.1.4