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.