BCInterface should be after core, since it is an utility for many
modules.

Introducing IFDEF

- the spaceData enum starts from 1 (rather than the default 0), to avoid crash
  if the string passed to setSpace does not match one of the stored ones
- spaceData and M_spaceMap now include also P0 elements and P2Bubble elements
  (the latter valid only in 3D)
- private becomes protected. This is needed in the ecm2 module's FESpaceManifold
  which we plan to bring soon into lifev
- some return values in the getters are turned into references rather than values
- changed a comment to a method, which referred to a vector as a velocity vector
  (problem specific)

Bug fix in StringUtility.cpp: we were potentially writing/reading out of a char array. Also, the number of digits of an integer i is not i/10, but Log(i).

Modified the interface of the PartitionIO and HDF5IO classes
to use Epetra_MpiComm objects explicitly. These classes are
only enabled if LifeV is configured with MPI and HDF5 and they
are only used with MPI.

If the user of the classes need to create an Epetra_Comm object
in his code, he should explicitly cast it to an Epetra_MpiComm
when using the PartitionIO class.

Replacing the test on the value of a pointer after a dynamic
cast with an assert. The dynamic cast should not fail as the
pointer should always always be an Epetra_MpiComm object.

 removed the warning "comparison between signed and unsigned integer expressions" in DOFInterface3Dto3D

The files HDF5IO.*pp and PartitionIO.hpp are not included
in compilation when TPL_ENABLE_HDF5 is off.

However, to prevent unforeseen problems with external apps using
LifeV, the LIFEV_HAS_HDF5 include guard has been added to these
files.