Petsc only supports initialisation through the ParameterGroup constructor.
Calling the default, non-arg constructor is a static error, and not
implementing it makes using it break compiles.
call_petsc.c was really a thin C wrapper around the call to petsc itself and
turns out was mostly unnecessary C++ emulation. This removes the file entirely
and ports its functionality into LinearSolverPetsc.cpp.
All features from the file should now be more readable as well as properly
utilising modern C++ features.
The patch uses the CHKERRXX macro from petsc to handle errors reported by
petsc, and currently does not handle this and give the control back to OPM's
error/throw system.
