Avoid the disused=yes tag for canals.
Use oblique fonts for water features.
Bump text sizes.
Write stream labels adjacent to thin lines.
Use a variable for water text.
Remove the catchall on road-text

This used to pick up lots of non-rendered features, as well as a few others
that will need to be re-instated elsewhere (e.g. admin boundaries).
Simplify the oneway tags.

We should be ignoring the '1' and 'true' versions, and beyond 'yes'
and '-1' we don't actually render anything.
Remove the catch-all on oneway arrows.

This removes them from unrendered highway values, and also removes them
from railways and waterways where they are of dubious interest and poor
colour choice respectively.
Remove the catch-all area-text, and add rules for green spaces and buildings.

There are probably other areas labels worth adding back in too.
Add admin boundary labels.

Ideally the labels would be offset to indicate the area covered, but
boundaries aren't in the polygon table.
Merge branch 'catch-alls-2'
Change the marina rendering to be a gradient outline.

Previously it was very eye-catching blue dashes, which was also
easily confused with cycle paths. The gradient help indicate which
side of the line is 'in' the marina, without colouring in the
whole thing.
Remove the vestigial remains of the admin catchall that never made it into carto.
Use admin polygons for labels, and offset them from the edges towards the interior.
Only use admin_levels from ways.

Effectively a rebase of #348.

This isn't ideal, since we should be able to (somehow) figure out
the max(admin_level) from all the ways and relations automatically,
but the osm2pgsql database layout doesn't make it easy.
Since mappers are commonly doing this algorithm anyway by hand
 - well, hey-ho. It's still an improvement in the end result.