ABI Navigator for Gtk releases

[Andrey Ponomarenko <andrewponomarenko yandex ru>]

Hello,

I'd like to present a new project called "ABI Navigator" for searching binary symbols (functions, global 
data, etc.) in Gtk and other open-source libraries: https://abi-laboratory.pro/index.php?view=navigator

The project allows to find out in which versions of the library some symbol is defined, added, removed or 
changed. The data is taken from the ABI Tracker project: https://abi-laboratory.pro/tracker/timeline/gtk+/

Example for gdk_rectangle_equal: 
https://abi-laboratory.pro/index.php?view=navigator&symbol=gdk_rectangle_equal#result

The project aims to help library users and maintainers to resolve issues with missed symbols and navigate 
through the reports in the ABI Tracker.

Have you ever encountered the "undefined reference" error or want to know whether the symbol is _stable_ 
enough to import in your code? Try to find it in the ABI Navigator!

Enjoy!