Added distFromSol as member variable and public functions for accessing the final iteration, change, residual and number of points in the NB.

Updating DCPSE

See merge request openfpm/openfpm_numerics!13

Deleted options for higher order upwind gradient from the Sussman redistancing because I cannot show numerical convergence for these.

Changed convergence criteria of Sussman redistancing, writing out with higher precision, having a check if NB already contains points. Backing up state before removing WENO/ENO option.

Changed convergence criterion of Sussman redistancing. Backing up state before removing WENO/ENO option.

Fixed updating of grid, removed temporary property Phi_nplus1_temp, changed print out to maximal values of change & redisual as opposed to average value like before.

Fixed getting location for placing the particles on the narrow band s.t. also valid for negative domain origin.

Adapted getting Surface Normal from Level Set Function s.t. normal has length = orthog. distance to surface.

Changed distance in placing of mirror particles. Now, normal vector should have length = distance to the surface.