integrate forward with different albedo subprocess
integrate forward with different albedo subprocess

removes the ‘icelat’ diagnostic if ‘ice line’ is not a subprocess of
the albedo subprocess

the  ‘icelat’ diagnostic is initialized again if an albedo subprocess
with ‘iceline’ is added to the model

brian-rose/climlab,cjcardinale/climlab,cjcardinale/climlab,brian-rose/climlab,cjcardinale/climlab