Change urban code to use downscaled atmospheric forcings

**Bill Sacks < sacks@ucar.edu > - 2016-11-15 05:04:24 -0700**
**Bugzilla Id:** [2377](http://bugz.cgd.ucar.edu/show_bug.cgi?id=2377)
**Bugzilla CC:** oleson@ucar.edu, rfisher@ucar.edu,

Most of the code uses the downscaled, column-level atmospheric forcings where relevant. However, the urban code still uses the gridcell-level, non-downscaled forcings in some places (search for 'not_downscaled' in the urban modules). This is simply because, when I was originally changing the code to use the downscaled forcings, it looked like it would be a fair amount of work to change the urban code to be fully consistent, so I punted on that.

This causes problems if you extend either the urban domain or the CISM domain so that the two overlap in any grid cells - i.e., if there are any active urban points in the CISM domain.

Once this is done, we can:

(1) Remove the check for column-gridcell equality in atm2lndMod: check_downscale_consistency

(2) Remove the code that I'm about to add to glc2lndMod: update_glc2lnd_topo that prevents downscaling over urban points