add color table used by r.lake into standard color tables

git-svn-id: https://svn.osgeo.org/grass/grass/trunk@68464 15284696-431f-4ddb-bdfa-cd5b030d7da7

lib/gis/colors.desc

@@ -43,4 +43,5 @@ slope: r.slope.aspect-type slope colors for raster values 0-90
 srtm: color palette for Shuttle Radar Topography Mission elevation
 srtm_plus: color palette for Shuttle Radar Topography Mission elevation (with seafloor colors)
 terrain: global elevation color table covering -11000 to +8850m
+water: water depth
 wave: color wave

lib/gis/colors/water

@@ -0,0 +1,2 @@
+0% 0:240:255
+100% 0:50:170