Work in progress on binning features in overzoom (#258)

* Factoring out tilestats management from GeoJSON file reading

* Move code around so overzoom can link against parse_layers

* Read the file of bins

* Plumb the bins through to overzoom()

* Some zip code bins to test with

* (Currently non-functional) test of binning

* Starting to spell out the bin matching loop

* Can't flatten points, so don't flatten bins either

* More fleshing out bin traversal

* Bounding box of tile-relative mvt geometry

* Smallest enclosing tile from bbox

* Most of the bin scan

* Add point in polygon check. It crashes.

* Find the matching bins

* GDAL-style bounding boxes have eaten my brain

* Make some features to bin into

* Increment a count as features are found to be within the bins

* Fix longitude wraparound in overzoom bins

* Fix the tests

* Push off attribute copying until after bin assignment

* Carry sum of numeric attributes into the bins

* Also add mean, min, and max

* Add --calculate-feature-index since I keep needing it for testing

* Add an option to accumulate sum/mean/max/min/count of all numeric attrs

* Don't bake in tippecanoe:mean, since we redo it from sum and count

* Forgot to update this test fixture after removing tiled mean

* Update version and changelog

man/tippecanoe.1

@@ -694,6 +694,8 @@ the line or polygon within one tile unit of its proper location. You can probabl
 \fB\fC\-ag\fR or \fB\fC\-\-calculate\-feature\-density\fR: Add a new attribute, \fB\fCtippecanoe_feature_density\fR, to each feature, to record how densely features are spaced in that area of the tile. You can use this attribute in the style to produce a glowing effect where points are densely packed. It can range from 0 in the sparsest areas to 255 in the densest.
 .IP \(bu 2
 \fB\fC\-ai\fR or \fB\fC\-\-generate\-ids\fR: Add an \fB\fCid\fR (a feature ID, not an attribute named \fB\fCid\fR) to each feature that does not already have one. There is currently no guarantee that the \fB\fCid\fR added will be stable between runs or that it will not conflict with manually\-assigned feature IDs. Future versions of Tippecanoe may change the mechanism for allocating IDs.
+.IP \(bu 2
+\fB\fC\-aX\fR or \fB\fC\-\-calculate\-feature\-index\fR: Add a \fB\fCtippecanoe:index\fR field to each feature, giving its index in the quadkey or hilbert sequence.
 .RE
 .SS Trying to correct bad source geometry
 .RS
@@ -904,7 +906,7 @@ Linux:
 .PP
 .RS
 .nf
-sudo apt\-get install build\-essential libsqlite3\-dev zlib1g\-dev
+sudo apt\-get install gcc g++ make libsqlite3\-dev zlib1g\-dev
 .fi
 .RE
 .PP