Quick bug fix in getSolution (#226)

When you call getSolution with multiple families the values calculated by the earlier families are zeroed on the iteration. 
I don't believe this was ever the intended behavior and frankly I'm surprised this was left on unfixed for so long.

src/solver/surfaceIntegrations.F90

@@ -959,7 +959,7 @@ subroutine getSolution(famLists, funcValues, globalValues)
        ! Extract the current family list
        nFam = famLists(iGroup, 1)
        famList => famLists(iGroup, 2:2+nFam-1)
-       funcValues = zero
+       funcValues(:, iGroup) = zero
        localVal = zero
 
        do sps=1, nTimeIntervalsSpectral