Including hdf5.h disables MPI C++ bindings

In Ubuntu Raring, including "hdf5.h" from the libhdf5-openmpi-dev
package completely disables the MPI C++ bindings. This leads to
weird errors and regressions compared to previous versions of
Ubuntu.

For example, to reproduce:

$ cat test.cpp
#include <hdf5.h> // disables MPI C++ bindings
#include <mpi.h>
int main() {
  MPI::Init();
  printf("I'm %d of %d\n", MPI::COMM_WORLD.Get_rank(),
MPI::COMM_WORLD.Get_size());
  MPI::Finalize();
}

$ mpicxx -o test test.cpp
test.cpp: In function ‘int main()’:
test.cpp:4:3: error: ‘MPI’ has not been declared
test.cpp:5:28: error: ‘MPI’ has not been declared
test.cpp:5:56: error: ‘MPI’ has not been declared
test.cpp:6:3: error: ‘MPI’ has not been declared

The fix for this bug is to remove 'skip_cxx_inclusion.diff' from
debian/patches/series.

There has been some discussion of this bug on the Debian bug
tracker (http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=686926).
However there hasn't been much action since the package is in
experimental. With the release of Raring nearing, I suggest
that we remove this patch from Ubuntu.

$ apt-cache policy libopenmpi-dev
libopenmpi-dev:
  Installed: 1.4.5-1ubuntu1
  Candidate: 1.4.5-1ubuntu1
  Version table:
 *** 1.4.5-1ubuntu1 0
        500 http://mirror.anl.gov/pub/ubuntu/ raring/universe amd64 Packages
        100 /var/lib/dpkg/status

$ apt-cache policy libhdf5-openmpi-dev
libhdf5-openmpi-dev:
  Installed: 1.8.9-1~exp3
  Candidate: 1.8.9-1~exp3
  Version table:
 *** 1.8.9-1~exp3 0
        500 http://mirror.anl.gov/pub/ubuntu/ raring/universe amd64 Packages
        100 /var/lib/dpkg/status