Added simple terrain and other developments
- Terrain grid based on sfhill and hypgrid3D.
- Flat terrain grid now used distfunc.py for more accurate spacing in the vertical direction.
- Moved origin to wind farm center for all cases.
- Increased calibration grid dimensions to better represent the wind farm grid.
- Increased default domain height to 25Dref.
- Added 6 different force methods, including AD airfoil methods.
- Added AD polar grid generation.
- Added 9 test cases.
- Added wdgrid variable to cases and grids.
- Removed all non-python input files from rans_lib.
- Added post processing of flow for planes and points.
- Clean up.