1) added #pragma warning(disable:4251) to slivr to remove dll-interface warnings (removed 386 warnings on Windows)

'size_t' to 'int' conversions (mostly when using .size() of an stl containter)

2) 'return' : conversion from 'size_t' to 'int' (cast return to 'int')
3) Change use of 'int' to 'size_t' when 'size_t' is more appropriate.
4) Change use 'size_t' to 'int' when 'int' is more appropriate
5) Cast arguments to functions from 'size_t' to 'int' when 'int' is expected.
6) use 'vtkIdType' when calling vtkDataArry->GetNumberOfTuples()
7) use 'int' when calling vtkDataArray->GetNumberOfComponents()

Reduced warnings on Windows from 6633 down to 4900.

git-svn-id: http://visit.ilight.com/svn/visit/trunk/src@21610 18c085ea-50e0-402c-830e-de6fd14e8384