[Dcmlib] Removal of virtual DictEntries : not so straight

[Jean-Pierre Roux]

Hi.

It wont be so straight :

Virtual DictEntries were used in 2 cases :
- When the 'explicit' VR found in the file is different than the one 
found in dicomV3.dic
   this can only appear for 'context dependant VR' (Pixel Data, Palette 
Color, that can be OW or  OB, ou US, for instance)
   this can be solved easyly by adding a char array 'Vr' to the 
attributes of the DocEntry, instead of creating a virtual DictEntry.
   When we process any DocEntry, we use all the attributes (Group, 
Element VM, Name, but he VR),  of the standard DictEntry.

-When we find a 'private element' (belonging to a Shadow group), or to a 
Public Group, with a never defined before Element Number,
  a Virtual DictEntriy was created. If we don't do, we have to store 
Group, Element  as well,  inside the DocEntry (4 more bytes), and use them
  when the pointer to the DictEntry is == 0.

Since VM and Name cannot be stored in the file, we don't have any 
special trouble with them :
either the DictEntry exists, and we use its VM and Name values
or it dosn't, then it's GDCM_UNFOUND.

No objection ?
JP