David Turner authored May 22, 2021 and Werner Lemberg committed May 24, 2021

This commit adds files necessary to build the demo programs,
including `ftinspect`, with the Meson build system.

* meson.build, graph/meson.build, src/ftinspect/meson.build: New
build files for Meson.
* subprojects/freetype2.wrap, subprojects/libpng.wrap,
subprojects/zlib.wrap: New subproject files for Meson.
* README.meson: New file.
* README, .gitignore: Updated.