render beach from z9
Change POIs displayed at z15 and z16 as discussed on #689

makes #70 less severe or maybe even fixed
follow CartoCSS Style Guidelines
"Always specify zoom levels as either >= or < . Don't use = or =< or >"
render beach from z10
Create new multi-line shields

This expands the shield generation script to cover multi-line shields,
and commits those shields. It doesn't yet use them.
Split concurrent refs into a multi-line shield

This new SQL takes the refs for a way, splits them on ;, and rejoins
them with newlines. When doing this it also calculates the number of lines
and the length of the longest line.

Fixes #670 as best as possible pre-Mapnik 3.
Also fixes #701
Merge branch 'master' into multiline_split_refs
metatile alignments
Delete allotments_3-1.png
rebase allotments.png and remove comment from mss
Merge branch 'allotment-metatile' of github.com:polarbearing/openstreetmap-carto into allotment-metatile
Refactor waterway bridges

* Rivers, streams, ditches and drains are now also rendered on bridges.
  This resolves https://trac.openstreetmap.org/ticket/3005.
* Canals on bridges now have a width consistent with canals not on bridges.
Make minimum landuse zoom levels more consistent

The minimum zoom levels are currently rather inconsistent. For example meadow
and farmland have a different minimum zoom level. This PR aims to improve this.

This PR lets all major landuse start at z10 (like most do already), except for
wood / forest. Smaller objects will start at z13.

Concrete changes in minimum zoom levels:

* tourism=camp_site, tourism=caravan_site, tourism_picnic_site from z13 to z10
* landuse=quarry from z11 to z10
* landuse=garages from z12 to z13
* landuse=farmyard, landuse=farm, landuse=farmland from z9 to 10
* landuse=village_green from z11 to z10
* natural=desert from z8 to z10 (solves partially #773)
* aeroway=apron, aeroway=aerodrome from z12 to z10
* highway=services, highway=rest_area from z14 to z10
Render names on junctions

This renders names of junction=yes and junction=roundabout.
Rendering is similar to highway=motorway_junction.
Change junction rendering

* Also render name for traffic_signals without junction tag
* Don't render junction names on roundabouts
* Render junctions in black and in a smaller font
* Offset junction names only when the traffic signal icon shows
* Start rendering junctions from z14
* Wrap lines
Clean up highway area label

* Render names on all types of highway areas, not just highway=pedestrian
* Make minimum zoom level depend on area size
Correct order secondary vs tertiary highway

This resolves #862.
Remove polygon-gamma

polygon-gamma was left over from the XML conversion, and doesn't actually
seem to help anything

Fixes #73
Superceeds #867
Clean up and reformat water area SQL

This reformats the water SQL, and eliminates unused and hardly used
mistaken taggings for water.

Cross-reference #204
Don't return way_area for water areas

We're not using way_area, so don't return it