Improve quality of coalescing-as-needed; add options to limit feature count (#25)

* Add an option to limit geometry vertex count

* Update docs and changelog

* Track desired feature count and geometry size in strategies

* Remove dead code for a long-forgotten inaccessible option

* Fix the option name in changelog

* Refine coalesce-smallest to only coalesce onto other small features

* Clean polygons before coalescing-as-needed

* Don't accumulate tiny polygon holes as negative dust

* Add the option not to limit the feature count at maxzoom

* Add options to limit feature count more abruptly in each tile

* Revert "Add the option not to limit the feature count at maxzoom"

This reverts commit ace173ab7a.

* Revert "Fix the option name in changelog"

This reverts commit 38dbce8405.

* Revert "Add an option to limit geometry vertex count"

This reverts commit d379fdf06b.

* Remove test for reverted option

* Remove more leftovers from geometry size limiting

* Update changelog

tile-join.cpp

@@ -619,6 +619,8 @@ void handle_strategies(const unsigned char *s, std::vector<strategy> *st) {
 							(*st)[i].tiny_polygons += v->value.number.number;
 						} else if (strcmp(k->value.string.string, "tile_size_desired") == 0) {
 							(*st)[i].tile_size += v->value.number.number;
+						} else if (strcmp(k->value.string.string, "feature_count_desired") == 0) {
+							(*st)[i].feature_count += v->value.number.number;
 						}
 					}
 				}