v0.7.58

• Added -symbols type=pie for making pie and donut chart symbols. Wedge sizes come from values=, wedge colors from fills= and the size of the symbol from radius=. Adding hole= makes a donut; a negative hole= is measured inward from the outer radius, for a band of wedges of a fixed width.
• -repel now supports pie, donut and ring symbols, in addition to circles.
• Fixed parsing of shorthand hex colors (e.g. #f90) and of the alpha channel of 8-digit hex colors (e.g. #ff000080).
• Handle missing layers in .gpkg files with a warning.
• Added support for importing zipped datasets from stdin, including .kmz (e.g. cat data.shp.zip | mapshaper -i - -o out.json). Previously, a .zip had to be unpacked into files on disk before importing.