Disable ENABLE_MPI_CUDA by default
Simplify execution configuration construction

Now there is only one constructor, called once.
Autotune cell list block size
Autotune block sizes for harmonic improper
Autotune harmonic bond block sizes
Autotune harmonic dihedral
Autotune angle harmonic block size
Autotune angle.cgcmm
dpdlj was still calling setBlockSize
Autotune nlist filter kernel block size
Autotune pair.table block size
Autotune bond.table block size.
Tune table angle block size
Autotune block size for table dihedral
Autotune block size in pair tersoff
Autotune EAM forces
Autotune external potentials
Remove old tuning code
Merge autotuner-complete: fixes #291

* autotuner-complete:
  Remove old tuning code
  Autotune external potentials
  Autotune EAM forces
  Autotune block size in pair tersoff
  Autotune block size for table dihedral
  Tune table angle block size
  Autotune bond.table block size.
  Autotune pair.table block size
  Autotune nlist filter kernel block size
  dpdlj was still calling setBlockSize
  Autotune angle.cgcmm
  Autotune angle harmonic block size
  Autotune harmonic dihedral
  Autotune harmonic bond block sizes
  Autotune block sizes for harmonic improper
  Autotune cell list block size
Fix nlist small box checks in 2D