Re #7424. Turn of packing for the Intel compiler.

With the present set of member variables it makes no difference and,
for the most recent compiler version, leads to a warning every time the
header is included (which is a lot!).
N.B. The packing also has no effect with gcc but I've left it on there.

Code/Mantid/Framework/MDEvents/inc/MantidMDEvents/MDBoxBase.h

@@ -24,7 +24,9 @@ namespace Mantid
 namespace MDEvents
 {
 
+#ifndef __INTEL_COMPILER // As of July 13, the packing has no effect for the Intel compiler and produces a warning
 #pragma pack(push, 4) //Ensure the structure is no larger than it needs to
+#endif
 
   //===============================================================================================
   /** Templated super-class of a multi-dimensional event "box".
@@ -378,7 +380,9 @@ namespace MDEvents
 
   }; //(end class MDBoxBase)
 
+#ifndef __INTEL_COMPILER
 #pragma pack(pop) //Return to default packing size
+#endif