Cleanups from code review

Makefile

@@ -120,7 +120,7 @@ testargs = \
 %.json.check:
 	./tippecanoe -q -a@ -f -o $@.mbtiles $(call testargs,$(patsubst %.json.check,%,$(word 4,$(subst /, ,$@)))) $(foreach suffix,$(suffixes),$(sort $(wildcard $(subst $(SPACE),/,$(wordlist 1,2,$(subst /, ,$@)))/*.$(suffix)))) < /dev/null
 	./tippecanoe-decode -x generator $@.mbtiles > $@.out
-	diff $@.out $(patsubst %.check,%,$@)
+	cmp $@.out $(patsubst %.check,%,$@)
 	rm $@.out $@.mbtiles
 
 # Don't test overflow with geobuf, because it fails (https://github.com/mapbox/geobuf/issues/87)
@@ -137,7 +137,7 @@ fewer-tests: tippecanoe tippecanoe-decode geobuf-test raw-tiles-test parallel-te
 	for i in $(wildcard $(subst $(SPACE),/,$(wordlist 1,2,$(subst /, ,$@)))/*.json.gz); do gzip -dc $$i | ./tippecanoe-json-tool -w | ./node_modules/geobuf/bin/json2geobuf > $$i.geobuf; done
 	./tippecanoe -q -a@ -f -o $@.mbtiles $(call testargs,$(patsubst %.json.checkbuf,%,$(word 4,$(subst /, ,$@)))) $(foreach suffix,$(suffixes),$(addsuffix .geobuf,$(sort $(wildcard $(subst $(SPACE),/,$(wordlist 1,2,$(subst /, ,$@)))/*.$(suffix))))) < /dev/null
 	./tippecanoe-decode -x generator $@.mbtiles | sed 's/checkbuf/check/g' | sed 's/\.geobuf//g' > $@.out
-	diff $@.out $(patsubst %.checkbuf,%,$@)
+	cmp $@.out $(patsubst %.checkbuf,%,$@)
 	rm $@.out $@.mbtiles
 
 parallel-test: $(eval SHELL:=$(ADVSHELL))

README.md

@@ -341,7 +341,7 @@ Parallel processing will also be automatic if the input file is in FlatGeobuf fo
  * `-ae` or `--extend-zooms-if-still-dropping`: Increase the maxzoom if features are still being dropped at that zoom level.
    The detail and simplification options that ordinarily apply only to the maximum zoom level will apply both to the originally
    specified maximum zoom and to any levels added beyond that.
- * `extend-zooms-if-still-dropping-maximum=`_count_: Increase the maxzoom if features are still being dropped at that zoom level
+ * `--extend-zooms-if-still-dropping-maximum=`_count_: Increase the maxzoom if features are still being dropped at that zoom level
    by up to _count_ zoom levels.
  * `-R` _zoom_`/`_x_`/`_y_ or `--one-tile=`_zoom_`/`_x_`/`_y_: Set the minzoom and maxzoom to _zoom_ and produce only
    the single specified tile at that zoom level.

man/tippecanoe.1

@@ -403,7 +403,7 @@ Parallel processing will also be automatic if the input file is in FlatGeobuf fo
 The detail and simplification options that ordinarily apply only to the maximum zoom level will apply both to the originally
 specified maximum zoom and to any levels added beyond that.
 .IP \(bu 2
-\fB\fCextend\-zooms\-if\-still\-dropping\-maximum=\fR\fIcount\fP: Increase the maxzoom if features are still being dropped at that zoom level
+\fB\fC\-\-extend\-zooms\-if\-still\-dropping\-maximum=\fR\fIcount\fP: Increase the maxzoom if features are still being dropped at that zoom level
 by up to \fIcount\fP zoom levels.
 .IP \(bu 2
 \fB\fC\-R\fR \fIzoom\fP\fB\fC/\fR\fIx\fP\fB\fC/\fR\fIy\fP or \fB\fC\-\-one\-tile=\fR\fIzoom\fP\fB\fC/\fR\fIx\fP\fB\fC/\fR\fIy\fP: Set the minzoom and maxzoom to \fIzoom\fP and produce only