Move shelter icon to SVG

[kocio-pl]

Implements part of #1165.

Simple vector replacement of a raster shelter icon:

[pnorman]

We use name.size.ext more than name-size.ext, so let's move to that at the same time.

[kocio-pl]

IIRC all my icons was made like this - probably looking at some @nebulon42 files, I guess. I was never sure, because we have both formats mixed, but I had more serious problems, so never touched it. If we decide to make them all the same, it probably deserves its own cosmetic patch.

[kocio-pl]

Just a cosmetic change so the icon looks better when enlarged (probably not visible on osm-carto):

[nebulon42]

While you're at it, I would suggest removing the rain as it just adds unnecessary clutter IMO.

[imagico]

I think the rain is important to indicate the function, otherwise it is just some kind of building.

[HolgerJeromin]

I would keep the rain, too.

[kocio-pl]

I was thinking about it too and came to the conclusion that otherwise it's not clear what type of building/roof is this. I like it more with rain.

[pnorman]

I like the rain, even though the clarity isn't perfect, mis-interpreting it is still likely to get the idea of sheltering across.