Should close issue #2854 .  I have added a multiplying function to RichardsPiecewiseLinearSinkFlux.  Amended: got rid of feproblem - all Side postprocessors have _dt already.
Merge pull request #2860 from WilkAndy/feature_2854

Should close issue #2854 .  I have added a multiplying function to Richa...
Merge commit '91d1c94d19bc5de9ce73a12fbaa6102fe079ef0f'