Upgrade to tools v5 - rm import-osm, new downloader... (#785)

Update to tools v5. See https://github.com/openmaptiles/openmaptiles-tools/releases/tag/v5.0.0 for the list of all changes. Other OMT-repo specific changes:

* removes `import-osm` docker usage, replacing it with `openmaptiles-tools`
* quickstart builds faster because it uses postgres with preloaded water, natural earth, and lake centerlines tables.

### Makefile targets
* `tools-dev` will open a shell in a docker to experiment and debug (instead of `import-sql-dev` and `import-osm-dev`)
* separated `start-maputnik` from `start-postserve`
* renamed `clean-docker` into `db-destroy` to make it more explicit
* cleaner `db-start`, `db-stop`, `db-destroy` targets
* `db-start-preloaded` is the same as `db-start`, except that it uses `postgis-preloaded` -- an image with preloaded water, natural-earth, and lake centerline data
* `db-start` will not recreate the container if it already exists -- this way if it was started as preloaded, it will not be rebuilt.
* better output messages

### Quickstart
* uses `postgis-preloaded` image by default to make quickstart quicker.  To start with a clean db, pass 2 parameters to quickstart, e.g. `./quickstart.sh albania empty`

layers/building/building.sql

@@ -102,8 +102,8 @@ RETURNS TABLE(geometry geometry, osm_id bigint, render_height int, render_min_he
         -- etldoc: osm_building_polygon -> layer_building:z14_
         SELECT DISTINCT ON (osm_id)
            osm_id, geometry,
-           ceil( COALESCE(height, levels*3.66,5))::int AS render_height,
-           floor(COALESCE(min_height, min_level*3.66,0))::int AS render_min_height,
+           ceil(COALESCE(height, levels*3.66, 5))::int AS render_height,
+           floor(COALESCE(min_height, min_level*3.66, 0))::int AS render_min_height,
            material,
            colour,
            hide_3d