BUG: #1761: make sure OpenMP runtime is loaded by the main executable

The number of threads used by OpenMP is set to the same number of threads used by ITK.

The original goal of this MR is also to load the OpenMP runtime during the main executable, not when loading an OTB application. It is causing crashes at the closure in several MachineLearning tests on windows (https://dash.orfeo-toolbox.org/testDetails.php?test=91541197&build=341760)

you don't need to remove the calls from where they are currently?

It is OpenMP, not MPI.

I think we can have the same situation between OpenMP and MPI, as between ITK threads and MPI : they multiply. This is why I propose that ITK_GLOBAL_DEFAULT_NUMBER_OF_THREADS also applies to the number of OpenMP threads.

Tested on dashboard, the tests failing are not related to this MR. The machine learning tests failing on Windows are gone. Missing 1 vote to merge.

merged

mentioned in commit a39cb76d

mentioned in issue #1722 (closed)

changed milestone to %7.0.0