Remove accidentally added test data files

In commit 352e3122 (Add test for vtkOpenFOAMReader, 2013-12-24) we
accidentally added files prefixed in "._" in addition to the actual data
files.  These files aren't real and, when you archive and untar a vtk
release, produce file exists warnings.

Change-Id: I13b600357f1b9712d55d8c0284c97fd1b0255683

Testing/Data/OpenFOAM/cavity/._.DS_Store.md5

-236abd9a367e5a390f2728fd931a7f1c

Testing/Data/OpenFOAM/cavity/._cavity.foam.md5

-d25e958d7091b7bea01729afa0be890f

Testing/Data/OpenFOAM/cavity/0.5/._U.md5

-d25e958d7091b7bea01729afa0be890f

Testing/Data/OpenFOAM/cavity/0.5/._p.md5

-d25e958d7091b7bea01729afa0be890f

Testing/Data/OpenFOAM/cavity/0.5/._phi.md5

-d25e958d7091b7bea01729afa0be890f

Testing/Data/OpenFOAM/cavity/0.5/uniform/._time.md5

-d25e958d7091b7bea01729afa0be890f

Testing/Data/OpenFOAM/cavity/0/._U.md5

-d25e958d7091b7bea01729afa0be890f

Testing/Data/OpenFOAM/cavity/0/._p.md5

-d25e958d7091b7bea01729afa0be890f

Testing/Data/OpenFOAM/cavity/1.5/._U.md5

-d25e958d7091b7bea01729afa0be890f

Testing/Data/OpenFOAM/cavity/1.5/._p.md5

-d25e958d7091b7bea01729afa0be890f

Testing/Data/OpenFOAM/cavity/1.5/._phi.md5

-d25e958d7091b7bea01729afa0be890f

Testing/Data/OpenFOAM/cavity/1.5/uniform/._time.md5

-d25e958d7091b7bea01729afa0be890f

Testing/Data/OpenFOAM/cavity/1/._U.md5

-d25e958d7091b7bea01729afa0be890f

Testing/Data/OpenFOAM/cavity/1/._p.md5

-d25e958d7091b7bea01729afa0be890f

Testing/Data/OpenFOAM/cavity/1/._phi.md5

-d25e958d7091b7bea01729afa0be890f

Testing/Data/OpenFOAM/cavity/1/uniform/._time.md5

-d25e958d7091b7bea01729afa0be890f

Testing/Data/OpenFOAM/cavity/2.5/._U.md5

-d25e958d7091b7bea01729afa0be890f

Testing/Data/OpenFOAM/cavity/2.5/._p.md5

-d25e958d7091b7bea01729afa0be890f

Testing/Data/OpenFOAM/cavity/2.5/._phi.md5

-d25e958d7091b7bea01729afa0be890f

Testing/Data/OpenFOAM/cavity/2.5/uniform/._time.md5

-d25e958d7091b7bea01729afa0be890f