update issue #194
@feelpp/core start working on hdf5/xmdf support.
Use implementation from LifeV and adapt it to Feel++
 - cmake changes to find support for HDF5
 - helper class Feel::HDF5 to ease the use of HDF5
update issue #194
@feelpp/core PartitionIO class writes a .h5 file from a partitioned mesh
(done in sequential) and is used to read the partitioned mesh in // 
not yet finished
update issue #194
@feelpp/core framework more or less in place, now need to fix implementation
Merge branch 'develop' of https://github.com/feelpp/feelpp into develop
update issue #161
spaces are parallel, need to deconnect global world comm
Merge branch 'develop' of https://github.com/feelpp/feelpp into develop