[DebianGIS] some explanation

["Francesco P. Lovergine" <frankie@debian.org>]

Hi Sylvestre and all

HDF5 has a long history of API violations even for minor revisions. That motivated
AFAIK use of a versioned library name in the past. In 1.8 series HDF Group finally
added an official SONAME to the libraries (C/C++/Fortran with and without MPI).
I adopted it instead of the Debian specific SONAME and library naming.
The current package (but for latest oversight about 1.8.3->1.8.4 migration with
the same SONAME) tries to be defensive on that regards, without sacrificing
name consistency. In fact the current HDF5 roadmap will change library source package
names at every minor/major release (also considering that the C++ ABI interface
could be easily broken at each update without notice) and will use virtuals such 
as libhdf5-1.8 and libhdf5-1.8.x to manage multiple MPI/serial packages and 
colliding sonames. That should suffice to ensure consistency among upgrades.

-- 
Francesco P. Lovergine