Do not try to link HDF5 static

The problem here is more cumbersome. some libraries like libdl are
also included by MPI and would be linked once static once dynamic.
upgrading MPI to static binding is to intrusive so we stay with libSplash
static only and everything else "default".
Add FindPNGwriter Module

... and use it in all CMake Projects
Close https://github.com/ax3l/pngwriter/issues/8
Add Comments About the Disabled HDF5
PNGwriter changes very seldom: shared linking

Compared to libSplash, PNGwriter changes very seldom
so that is a good case for shared linking in our
projects to reduce complexity (of double linked
shared/static libraries) with other modules.
Merge pull request #307 from ax3l/fix-SplashCMakeHDF5

Do not try to link HDF5 static
Merge pull request #308 from ax3l/topic-FindPNGwriter

FindPNGwriter Module and GOL ICC