Fix extents in hyper-tree grid geometry

Change-Id: I560c3636556a750dda80fe7bcf7156afaea23c89
Fix crash when empty input passed to particle reader

Change-Id: Ib896bd6f58a3ad792b8bbd53ef12ea4dd0996626
Remove redundant code in AMR grid connectivity test

Change-Id: I9380d11a668391ac61f86bf6f407db546a72b195
Replace ghost levels arrays with ghost types in structured grids

Change-Id: Iccfb55754269bf8da0f1d9494b3c0d90debf4a60
Set correct ghost types in vtkDataSet

Change-Id: Iffccfede96a7971c31da7d51419a78d4c7490daf
Replace ghost levels arrays with ghost types in StructuredAMRGridConnectivity

Change-Id: I00fa9b0a02bd8029e7e22e14c45d6ecbbde6b429
Fix StructuredGridConnectivity test

Change-Id: I42def29fabfa89010fc988a6acd48813d63f678b