Add ExternalData content links to test baselines

Change-Id: I7c6ab523d022f28256bb9d29e23ebacbcf6eafdd
vtkTestingMacros: Remove vtk_add_test_* baseline directory arguments

Baseline images are now referenced by ExternalData content links stored
directly in each module source tree.  Drop the old VTKData baseline
subdirectory name from the vtk_add_test_* signatures.

Change-Id: I5bdc7a5bf87fc7c8fa77dcd50b79f2f54d6eba31
Merge branch 'master' into use-ExternalData

We need to integrate changes made to tests into our branch.

Change-Id: Idcddf2c1c78b07cffd870d85365435c05feb0a6e
Update TestGraphLayoutView baseline

Update the test baseline to match the test update by commit 8ee7cfbf
(Initialize representation's scalar bar actors, 2012-12-06).

Change-Id: Iba7659736e3741f952d0be12fdb320d49f740143
Add script to upload content-linked external data files to MIDAS

Port the Utilities/Maintenance/ArchiveTestingData.py from ITK to VTK.

Add the VTK Community on the Kitware Midas server as a resource for
downloading VTK ExternalData.  This improves robustness against failed
connections with the Apache file server, protection against the other
server going down, and a web interface to examine and download the
individual files.

Add a script to upload all files corresponding to the content links in
the source tree to the Midas server.  Make the paths of the files mirror
the content link location within the source tree.  Obtain the files from
a local ExternalData object store.

Change-Id: I2dc9234d3ab0499dc2196e68d2c967d9445e10d7