this is part of the release maintainance. in this context "core
headers" means the ones which do not include the well model headers,
and only those which are concerned with non-exotic functionality,
e.g., the PolyhedralGrid and ALUGrid vanguards are not changed.
reads tracer input from deck, solves tracer equation fully implicit as a post processing step in endTimeStep
tested on a simple modified SPE1CASE1 deck and compared with eclipse
TODO: restart and parallel
