Issue #98 Port sandbox/gas/obrf/ case from examples/gasdyn/obrf/ for running through only.  The results are still incorrect so far.
Issue #98 remove unnecessary import.
Merge bookmark master to bookmark gas.
Ref issue #98 Trouble-shoot the gas solver nan error and make sandbox/gas/obrf/ smoothly execute.
Merged in yungyuc/scdev (pull request #43)

Enable solvcon.parcel.gas solver