1. Using container_cairo_pango for running tests.
2. Added Dockerfile to create docker container for building litehtml
tests
3. Added script run_render_tests.sh to build litehtml tests in the
docker container
4. Added render2png target (cmake -DLITEHTML_BUILD_RENDER2PNG). This
utility allow to render html file into a png file.
5. Tests building are off by default.
Use "cmake -DLITEHTML_BUILD_TESTING=ON" command to buid tests
6. Added container_cairo_pango::get_font_options. Overwrite this method
to control fonts rendering.
Render tests are .htm files in litehtml/test directory.
Tests starting with "-" are disabled.
Correct rendering is in corresponding .htm.png file.
To generate .png file, run ctest from litehtml/build. The test will fail
and create xxx.htm-FAILED.png file. Rename it to xxx.htm.png
One ASCII raster font with 3 sizes is supported, see litehtml/containers/test/fonts. This should be enough for tests.
Border painting is supported, only solid borders.
Backgrounds, images and list markers are not supported.
