Added if (*ierr) check in two Fortran stubs where it was missing, to properly propogate error code up

Commit-type: bug-fix
Reported-by: Tim Steinhoff kandanovian@gmail.com

initialize a few variables to 0 to prevent compiler complaints

fix 'next' test fail: Change visibility of PetscViewerHDF5Load_Internal to PETSC_EXTERN.

Since it is possibly used across multiple shared libraries. Renamed to PetscViewerHDF5Load.

fix 'next' test fail: Vaclav, class is a keyword in C++

PetscViewerHDF5Load_Internal: check that dataset and PETSc has the same scalar type (complex/real)

PetscViewerHDF5Load_Internal: fix unitsize for complex numbers

my PetscViewerHDF5Read*_Internal functions privatized - shouldn't be needed elsewhere

add PetscViewerHDF5Load_Internal calling all my PetscViewerHDF5Read*_Internal functions

PetscViewerHDF5ReadSizes: added doc and fortran interface

PetscViewerHDF5OpenGroup: changed /*@C to /*@

PetscViewerHDF5ReadInitialize_Internal: fixed for groupname=NULL

PetscViewerHDF5ReadArray_Internal impl.

PetscViewerHDF5ReadInitialize_Internal: create property list (taken from VecLoad_HDF5)

PetscViewerHDF5ReadSelectHyperslab_Internal impl.

HDF5ReadCtx: added timestep,complexVal,dim2 attributes

PetscViewerHDF5ReadSizes_Internal: renamed variables

PetscViewerHDF5ReadSizes_Internal: update PetscLayout instead of returning N,bs

PetscViewerHDF5ReadSizes_Internal: removed bsDimInd,lenDimInd,dim2 out args)

PetscViewerHDF5ReadInitialize_Internal: fail for complex data and non-complex petsc

PetscViewerHDF5ReadSizes: factored out PetscViewerHDF5Read{Initialize,Size,Finalize}_Internal

PetscViewerHDF5ReadSizes: support vectors stored as 1D array

PetscViewerHDF5ReadSizes moved from vecio.c to hdf5v.c

added PetscViewerHDF5OpenGroup documentation

PetscViewerHDF5OpenGroup moved from vecio.c to hdf5v.c

PetscViewerBinary: open a new file if we have been asked to append to a non-existing one

Note that the ASCII format already supports this, since fopen(filename,'a') opens the file when not present