implemented unconventional D3Q27 stencil by Abbas Fakhari

In the paper 3D phase-field is written :

As for the discrete velocity set of the D3Q27 lattice used for the hydro- dynamics, a slightly unconventional ordering was used in order to align the first 15 velocity directions with the D3Q15 model.

Therefore I also implemented this stencil with the name fakhari. For the D3Q15 stencil they used: premnath

merged

mentioned in commit 835f8e4d