Strange power variation when specifying turbine location with its geometrical coordinates

[moulin1024]

In the turbine.cuf, if the wind turbine location is specify with turb_loc, instead of the grid point index. A power drop will appear for certain location, even if the coordinates is actually at an integer index point!

Current ad-hoc fix: nint(turb_loc/dx)*dx, basically roll back to the index specification but with geometrical coordinates input.