Making the ILDG support optional

tests/hmc/Test_hmc_WilsonGauge_Binary.cc

@@ -81,6 +81,10 @@ class HmcRunner : public BinaryHmcRunner {
     TheAction.push_back(Level1);
 
     // Add observables
+    // options for checkpointers
+    //BinaryHmcCheckpointer
+    //ILDGHmcCheckpointer
+    //NerscHmcCheckpointer
     ILDGHmcCheckpointer<BinaryHmcRunner::ImplPolicy> Checkpoint(
         HMCPar.conf_prefix, HMCPar.rng_prefix, HMCPar.SaveInterval, HMCPar.format);
     // Can implement also a specific function in the hmcrunner