Merge branch 'reduction' into 'master'

runtime/starpu/CMakeLists.txt

runtime/starpu/codelets/codelet_ipiv.c

runtime/starpu/codelets/codelet_zgetrf_batched.c

runtime/starpu/codelets/codelet_zgetrf_blocked.c

runtime/starpu/codelets/codelet_zgetrf_percol.c

runtime/starpu/codelets/codelet_zipiv_allreduce.c

runtime/starpu/control/runtime_descriptor_ipiv.c

runtime/starpu/include/chameleon_starpu.h.in

runtime/starpu/include/cppi_interface.h

runtime/starpu/interface/cppi_interface.c

testing/CTestLists.cmake

testing/testing_zgetrf.c