Pixel align the ford icon

[meased]

Fixes #2822

The arrow is a little fatter because arrows need to end on a point to look sharp and therefore need to have an odd height. One water line is removed to reduce the weight a little and to keep the design language the same as waterfall, public_bath, beach_resort, and water_park

Icon before:

Icon after:

https://www.openstreetmap.org/#map=16/45.3493/-121.6580
Before:

After:

[matthijsmelissen]

Looks good.

The antialiasing at the bottom might look better with the water moved up one pixel?

[kocio-pl]

I would rather make the waves 1 px higher than move them up, to make them more visible.

[dieterdreist]

I agree with Kocio, the waves are not very recognizable now, maybe making them higher will improve readability

[imagico]

For reference: The original discussion for the current ford icon can be found in #1625.

[meased]

The waves are identical to the ones used in the public_bath, beach_resort, and water_park icons (when I did the waterfall icon different waves were used, though I probably shouldn't have). If it is not recognizable here, then I feel the other icons should be updated too (which I'm not opposed to doing).

The waterfall icon starts the waves out of sync, which I think makes it look more natural and less like a triple "M", and obviously if the waves are bigger they will be more recognizable (at the expense of less space to draw in the top part). Here are the thick/thin/tall/short variations with offset waves:

[kocio-pl]

4 is the best for me.

[geozeisig]

Why do you use a loupe? In my eyes, the icon looks amazing good in 1: 1 mode.

[meased]

I liked 3 and 4, @kocio-pl liked 4, so unless anyone else weighs in I have updated this PR to use icon 4.

[matthijsmelissen]

Thanks!