Draw OSM glaciers

[almccon]

Here's Mt. Baker at z9, showing only the landcover data. Nice white-topped mountain:

Then at z10 we start drawing national forests, and this ice-covered peak looks solid green:

OSM has good glacier features... we should draw them:

...but I think I will have to pull out yet another OSM feature in imposm.

[almccon]

But then, why stop there? Perhaps part of the solution to #41 is to bring in even more landuse, landcover, and natural features from OSM, and more-or-less match their colors to the MODIS landcover raster. Going to give it a try, wish me luck.

[mojodna]

:four_leaf_clover:

[almccon]

Glaciers are looking good:

Mt. Baker:

Mt. Adams:

[almccon]

I also brought in a bunch of other landcover features, which look great:

[clhenrick]

Awesome!