improve cmake finding python packages that depends on libOpenCL.so when configuring on a frontend machine

added debug logs for redistribute and ghost exchange, corrected a critical bug for fortran ghost exchange

Re-enable HDF5 parallel interface. (reverting commit 9c195f33). It works only in a few specific cases (1d topology + cuting direction in the last varying direction)

Disable parallel hdf5 interface. In parallel simulations, one h5 file is written by each process, and joined through xmf 'JOIN' function on dataitems. It can be enabled with WITH_PARALLEL_HDF5 cmake flag