CRA-700: Background grids were deleted too soon.
CRA-505: Temp.
CRA-505, CRA-707: Removed the option of resample to a FFTGRid. Pull from upstream.
CRA-688, CRA-700: Writing fix for forward modelling.
CRA-505: Grid was not allocated in SetupDepthConversion.
Merge pull request #122 from enesvold/CRA-505

CRA-704
CRA-505: Merge with rhauge. Seis cube type was not set correctly in modelavodynamic.
CRA-505: Merge with enesvold.
Merge pull request #123 from hgolsen/CRA-505

Cra 707
#CRA-710 Surfaces are written to files in simbox setup
#CRA-505
#CRA-710 Fixed some warnings
Merge branch 'CRA-710' into CRA-505