Adding 3D acoustics example
Adding Burgers' equation
Merge remote-tracking branch 'mjberger/3dreordered' into 3dreordered
Merge remote-tracking branch 'mjberger/3dreordered' into 3dreordered
Merge remote-tracking branch 'mjberger/3dreordered' into 3dreordered
Updating acoustics example for debugging
Merge remote branch 'grady/3dreordered' into 3dreordered
bug - used nvar instead of naux