Script for bootstrapping virtual environments
 Change order of requirements (easiest first)
 Add option to download netcdf4+hdf5 tarballs
 structure was missing in the call to tensor.symmetrize in plot_mdf.py
 Try to fix annoying problem with nosetests in the gui subpackage.
 More robust test in finite_diff
 Fix bug in abicheck
 Add fabfile for managing the repositories on the CECI clusters.
 Document fabile.py
 Use paral_kgb=0 in run_*.py scripts
 Code cleanup
 Solving protability problems on CECI clusters.