use cap: round for paths and roads

[matkoniecz]

I am not planning making PR due to very high complexity of style, but it seems that cap:round would be useful for paths

for example https://github.com/matkoniecz/cinnabar-style/commit/33aec7e90652b09c43c228e107579a86e9fb06da makes following difference at https://mapzen.com/tangram/play/?#20.00000/50.08020/19.88489

from

to

It affects not only baths - see bottom right of https://user-images.githubusercontent.com/13661397/27248826-e48fa0ae-5300-11e7-9349-2d1e065eb34d.png (spotted in https://github.com/westnordost/StreetComplete/pull/340)

[nvkelso]

Looks like the same cap: round fix could be applied to most Mapzen basemap styles.

I vaguely recall this not being done last year because it introduces a performance hit – we could address that by limiting to zoom 16 or 17+ only.

[sensescape]

fixed:

https://github.com/tangrams/cinnabar-style/commit/480557206f2e82c50b069dab87ad3c261cd21d1a

[nvkelso]

Fixed in https://github.com/tangrams/cinnabar-style/issues/42, but needs public release to CDN.