message: Minor CHANGELOG update.
diff: http://mfem.org
  -Not released yet
  -================
  +Development version, not released yet
  +=====================================
  +
  - Memory optimizations in the NCMesh class, which now uses 50% less memory in
  total. The average cost of an NC element (including the refinement hierarchy,
  but not including the temporary face_list and edge_list) is now only about 290
  