+* Split gdcmHeader through inheritance to create gdcmHeaderHelper
+ that would regroup all the heuristics above a gdcmHeader e.g. the
+ functions GetXsize(), GetXSpacing(), GetXImagePosition()...
+ Those functions are the one using the results of the parsing as
+ done by gdcmHeader to provide the user with heuristics above various
+ values found in the header (the simplest form being to default a value).
+* vtk/vtkGdcmHeader.cxx: if speed becomes a concern some changes can
+ be made a the cost of memory consumption (refer to header of
+ vtk/vtkGdcmHeader.cxx)
+* Add a GetVersion() global function.
+* gdcmElValSet::SetElValueLengthByNumber IMNSHO should be trashed.
+ It's only purpose is a onliner substitute to calling GetElValueByNumber
+ and then SetLength. This only obfuscates the caller code more than
+ clarifying it.
+ Besides the definition of gdcmElValSet::SetElValueLengthByNumber itself
+ it quite poor since it is a almost exact copy of
+ gdcmElValSet::GetElValueByNumber except for the returned code.
+ gdcmHeader::SetPubElValLengthByNumber (which is based on
+ gdcmElValSet::SetElValueLengthByNumber) is used nowhere...