complex conjugation when interpolating complex valued function

[bkang119]

While I can interpolate complex valued functions, e.g.,
grid = RectangleGrid([0., 1., 2.])
gridData = [1.0im, 2.0im, 3.0im]

the interpolated function returns complex conjugated values: E.g.,
interpolate(grid,gridData, [0.0])
gives 0.0-1.0im instead of 1.0im

[eschnett]

The code uses dot to perform the actual interpolation. Switching the arguments to the call to dot would resolve this.