Using the standard VTK_LEGACY_REMOVE mechanism to deprecate these, and
wrapping the definition of the vtkstd namespace in the standard ifdef
block. The generation of vtkstd should be completely removed in VTK 6.0.

If you still need vtkstd do not turn on VTK_LEGACY_REMOVE. This will
certainly be required by several other applications such as ParaView and
Slicer until they also remove their use of vtkstd.

Change-Id: I1dc2e4a6ff0aa98cbd6bd6e0dd054510ba00b7d5