You can always use an open-source tool like QGIS to open your shapefile and merge features using the built-in "merge selected features" tool (just select features, click merge, select attributes to inherit to the new merged feature, done).
This of course doesn't make much sense if we're talking about hundreds or thousands of merges. I myself was wondering the other day if it is possible to merge features "by attribute" in QGIS?
EDIT: Ok, I'm stupid, if you have a common attribute for all features you're going to "cluster" (like a province or county name) this would be a case for the dissolve tool. Open your shapefile, choose dissolve (in QGIS it's located at Vector > Geoprocessing Tools > Dissolve), select the column with the above mentioned common name, and start the process. This should hopefully (if I haven't misunderstood you) result in what you were looking for.
Try wrapping the features in the following:
{"type":"FeatureCollection","features":[
****ALL THE DATA HERE -- COMMA SEPARATED****
]}
and separating each feature with a comma.
For example, here's the first two features from the IE dataset:
{"geometry": {"type": "Point", "coordinates": [-6.422587, 53.293363]}, "type": "Feature", "id": "SG_41u80gC4971D4Gc0Fv1p8q_53.293363_-6.422587@1308163237", "properties": {"website": "http://www.buongiorno.com", "city": "Dublin", "name": "Buongiorno", "tags": ["mobile", "vas", "community", "social-networking", "connected-devices", "android", "tablets", "smartphones"], "country": "IE", "classifiers": [{"category": "Professional", "type": "Services", "subcategory": "Computer Services"}], "href": "http://api.simplegeo.com/1.0/features/SG_41u80gC4971D4Gc0Fv1p8q_53.293363_-6.422587@1308163237.json", "address": "Lake Drive City West Digital Park", "owner": "simplegeo", "postcode": "3050"}}
{"geometry": {"type": "Point", "coordinates": [-6.250848, 53.339347]}, "type": "Feature", "id": "SG_1dnWbWIg8hX3VyfUKIDRz9_53.339347_-6.250848@1308163237", "properties": {"website": "http://www.simchronise.com", "city": "Dublin", "name": "SIMchronise", "tags": ["mobile-solutions", "mobile-data", "data-synchronisation", "mobile-security", "backup", "restore", "mobile-contacts", "web-2.0-addressbook", "phonebackup"], "country": "IE", "classifiers": [{"category": "Professional", "type": "Services", "subcategory": "Computer Services"}], "href": "http://api.simplegeo.com/1.0/features/SG_1dnWbWIg8hX3VyfUKIDRz9_53.339347_-6.250848@1308163237.json", "address": "78 Merrion Square", "owner": "simplegeo", "postcode": "Dublin2"}}
... and here they are as a GeoJSON FeatureCollection:
{"type":"FeatureCollection","features":[
{"geometry": {"type": "Point", "coordinates": [-6.422587, 53.293363]}, "type": "Feature", "id": "SG_41u80gC4971D4Gc0Fv1p8q_53.293363_-6.422587@1308163237", "properties": {"website": "http://www.buongiorno.com", "city": "Dublin", "name": "Buongiorno", "tags": ["mobile", "vas", "community", "social-networking", "connected-devices", "android", "tablets", "smartphones"], "country": "IE", "classifiers": [{"category": "Professional", "type": "Services", "subcategory": "Computer Services"}], "href": "http://api.simplegeo.com/1.0/features/SG_41u80gC4971D4Gc0Fv1p8q_53.293363_-6.422587@1308163237.json", "address": "Lake Drive City West Digital Park", "owner": "simplegeo", "postcode": "3050"}},
{"geometry": {"type": "Point", "coordinates": [-6.250848, 53.339347]}, "type": "Feature", "id": "SG_1dnWbWIg8hX3VyfUKIDRz9_53.339347_-6.250848@1308163237", "properties": {"website": "http://www.simchronise.com", "city": "Dublin", "name": "SIMchronise", "tags": ["mobile-solutions", "mobile-data", "data-synchronisation", "mobile-security", "backup", "restore", "mobile-contacts", "web-2.0-addressbook", "phonebackup"], "country": "IE", "classifiers": [{"category": "Professional", "type": "Services", "subcategory": "Computer Services"}], "href": "http://api.simplegeo.com/1.0/features/SG_1dnWbWIg8hX3VyfUKIDRz9_53.339347_-6.250848@1308163237.json", "address": "78 Merrion Square", "owner": "simplegeo", "postcode": "Dublin2"}}
]}
Best Answer
If you
docker run -v </path/to/output/dir>:/workdir/data -e MapboxAccessToken=<your token> -e QA_TILES=<name of country> developmentseed/skynet-data download-osm-tilesand then
docker run -v </path/to/output/dir>:/workdir/data -e MapboxAccessToken=<your token> -e QA_TILES=<name of country> developmentseed/skynet-data download-osm-tilesthen your MBTiles file will be rendered to PNGs in /path/to/output/dir/labels/color.