PngOptimizer 2.6.2 (Linux)

A new PngOptimizer for Linux is available. The main feature is a user interface redesign to match new Gnome standards.

Another "feature" is the fact you can now install PngOptimizer on Ubuntu through a PPA. It makes installation and updating easier.

sudo add-apt-repository ppa:psydk/pngoptimizer
sudo apt update
sudo apt install pngoptimizer

The PPA installation works for Ubuntu 16.04, 18.04, 19.04 and 19.10. However I could only test on Ubuntu 18.04 so far.

PngOptimizerCL (the command line version) is also provided in the same package.

In the future, I would like to make it an official package of Ubuntu, or Debian (as Ubuntu is based on) but I still need to figure out how to do that.

As these changes are only related to Linux, the Windows version is left unchanged.