Release notes for 0.19.0rc1

No binaries this time. Added a few meson options related to images. One of milestones was achieved, it is possible to play Tetris now in ELinks(You must bind rarely used key to action "toggle-ecmascript-keys"). If you want to search in google you must change User-Agent, and disable noscript in options.

If you build hubbub, add -DNDEBUG to CFLAGS, otherwise it trashes screen with debug printfs. For quickjs, similar. If you do not add -DNDEBUG to quickjs's CFLAGS, elinks will abort on exit (due to memory leaks).

For better CSS support, build against libcss library. Especially for "visibility: hidden" support, libcss recognizes more selectors.

I don't add new features to configure.ac myself, but will accept pull requests which add them.