LAYERS now standard_name, units had to be found via cf utility

@brandonmayer have a quick look at this

We lost the "units" when we went to the standard_name in the WMS LAYERS argument. Have to use the cf 'get_by_standard_name' utility now to get the appropriate dataset and then the units for display in the legend

for comparison (valid 20141120):
http://comt.sura.org/proxy_8081/wms/datasets/inundation_tropical_UND_ADCIRC_Hurricane_Ike_2D_final_run_with_waves/?LAYERS=sea_surface_height_above_geoid&TRANSPARENT=TRUE&STYLES=pcolor_average_jet_0_7.0_grid_False&FORMAT=image%2Fpng&TIME=2008-09-05T12%3A00%3A00&SERVICE=WMS&VERSION=1.1.1&REQUEST=GetLegendGraphic&SRS=EPSG%3A3857&LAYER=sea_surface_height_above_geoid

http://comt.sura.org/proxy_8080/wms/datasets/inundation_tropical_UND_ADCIRC_Hurricane_Ike_2D_final_run_with_waves/?LAYERS=sea_surface_height_above_geoid&TRANSPARENT=TRUE&STYLES=pcolor_average_jet_0_7.0_grid_False&FORMAT=image%2Fpng&TIME=2008-09-05T12%3A00%3A00&SERVICE=WMS&VERSION=1.1.1&REQUEST=GetLegendGraphic&SRS=EPSG%3A3857&LAYER=sea_surface_height_above_geoid