Squashed 'bx/' content from commit 4de65f8

git-subtree-dir: bx
git-subtree-split: 4de65f847460e103aab2c07729f6e1d5d00d4e68
Merge commit 'b878ef608be1373edd27f84e085e43ce62aff9cd' as 'bx'
integrated latest bgfx-release, started with wayland-backend, but doesn't work yet.