Try to warn user when 'DeflatedExplicitVR' Transfer Syntax found.

Try to warn user when 'DeflatedExplicitVR' Transfer Syntax found.
--> Still to be done :
find a trick to stop the processing.
--> Still to be done (*later*)
. find a trick to uncompress the whole Dataset and go on Parsing, whitout having
to create a temporary file
. find a trick not to uncompress the Pixel Group every time !