Label coordinate index variables with level

[jsemer]

In order to make the generated mappings a little clearer for human consumption, it would be nice if the printed listings of a mapping showed the level number as part of the coordinate index variables. For example:

Instead of:

for M ...
   for N ...
      for N...
         for M...

print:

for M1 ...
   for N1 ...
      for N0...
         for M0...