add osx.9 fix for netcdf4
Add in support for netcdf4 cpp bindings.
Add an example linux netcdf configuration.
Add a test to verify that netcdf and netcdfcpp builds correctly.
Move netcdf4 test to a namespaced test, also fix names of netcdf packages.
[fix-netcdf] use MPI compilers so HDF5 can be properly compiled/linked
Merge remote-tracking branch 'origin/master' into hashdist-ahmadia/fix_netcdf

Conflicts:
	.travis.yml
Fix netcdf/host-mpi (take 2)
Merge pull request #302 from hashdist/ahmadia/fix_netcdf

Ahmadia/fix netcdf