gtCrystFindFamilies : Reads hklsp list from a grain and find the corresponding hkl family. Saves hkl, thetatypesp, dspacingsp, mult info for each reflection assigned to the grain (sorting according to dspacing values - needs single values in this case).
                      Gives in the output extra info as thetatype, dpsacing, hkls, hklind for the complete list with the symmetrics.

Signed-off-by: Laura Nervo <laura.nervo@esrf.fr>