Rework/global edit to enforce type templating of fermion operators.

Allows multi-precision work and paves the way for alternate BC's and such like
allowing for example G-parity which is important for K pipi programme.
In particular, can drive an extra flavour index into the fermion fields
using template types.

lib/qcd/spin/Dirac.h

@@ -4,7 +4,6 @@ namespace Grid{
 
 namespace QCD {
 
-  const int SpinorIndex = 2;
 
   class Gamma {