Remove --merge-polygons-as-needed until it works well. Bump version.

CHANGELOG.md

@@ -1,3 +1,13 @@
+## 1.15.0
+
+* New strategies for making tiles smaller, with uniform behavior across
+  the whole zoom level: --increase-gamma-as-needed,
+  --drop-densest-as-needed, --drop-fraction-as-needed,
+  --drop-smallest-as-needed.
+* Option to specify the maximum tile size in bytes
+* Option to turn off tiny polygon reduction
+* Better error checking in JSON parsing
+
 ## 1.14.4
 
 * Make -B/-r feature-dropping consistent between tiles and zoom levels