+ * GDCM_NAME_SPACE::Debug::SetDebugOn();
+ *
+ * Warning : Warns the user when some oddity occured, and we used an heuristics
+ * to bypass the trouble.
+ * e.g. : SamplesPerPixel missing, we assume it's a grey level image
+ * e.g : Pixel Representation missing : we assume 'unsigned'
+ * (we hope our assumption is OK, but user may disagree.)
+ * Log : we display messages when anything is not Dicom Kosher
+ * e.g. : non even length field
+ * e.g : file is declared as Explicit VR, but a DataElement
+ * is Implicit
+ * e.g : a file holds an illegal group (0x0005, ...)
+ * Debug : We help developper to trace, at a glance, the execution.
+ * (before refining with a debugging tool)
+ *
+ * Setting ON Debug leads to set ON Warning (but not Log)
+ * Setting ON Log leads to set ON Warning (but not Debug)