Small things to fix that I keep forgetting about...

[r-lyeh]

• ui: abnormal behavior on osx.
• video: audio buffers may exhaust. do a better mixer.
• video: stutters shortly when fast seeking.
• editor: gizmo crashes sometimes.
• editor: gizmo make it better resolution independent.
• editor: gizmo handlers do overlap often.
• editor: 3-gizmos 1-view.
• render: billboards stopped working sometime ago.
• render: fx_end() should flush all retained renderers (debugdraw, sprites, ...)
• sprite: expose ortho-2d camera for sprites somehow.
• sprite: hud sprites (resolution independent, z-index, no fx).
• sprite: parallax, tiled map loader.
• sprite: normals, lighting.
• profile: ensure we add up different calls from matching section names.
• demo_script/demo_socket: might use some more fancy demo (windowed).
• demo_shadertoy: move logic to materials. then rename to demo_material.c
• pipeline: showcase pipeline per-asset options? turn models 90º
• demo_anims: ackward controller, not working yet
• demo_scene: two_sided option stopped working?
• demo_scene: fuse with demo_model? demo_editor+materials instead?
• demo_scene: bounding box should be enabled by default to showcase it.
• demo_pbr: move all rendering logic from this demo into fwk.c
• tcc+win: not working always, see Compile error clang/gcc Compile error clang/gcc #10
• clang-cl: not working because of faulty toolchain, see Compile error clang/gcc Compile error clang/gcc #10 hints here https://bugs.llvm.org/show_bug.cgi?id=25305
• https: not working in DLL form (tcc win)
• linux: cuttlefish /lib/x86_64-linux-gnu/libm.so.6: version GLIBC_2.27 not found (required by art/tools/libcuttlefish.so.2) (reported by procedural)
• win+nvidia+fullscreen: adaptive vsync not working ok (low/inconsistent framerate) (reported by sushil)