2023.12

Maintenance release:

new: steam api, demos\99-steam.c
new: lightmap api, demos\99-lmap.c (@zpl-zak)
new: audio_loop(), audio_playing() (@zpl-zak)
new: gui labels + sliders (@zpl-zak)
new: font_metrics() (@zpl-zak)
new: ui_font() (@zpl-zak)
new: ease_zero(), ease_one()
new: tools/glslcc
new: MAKE run

chg: expose vfs_reload() (@zpl-zak)
chg: gui_getskincolor() (via slice color) (@zpl-zak)
chg: optimized internal font cache tables for codepoints
chg: rebuilt tools (ass2iqe, iqe2iqm) (win, lin)
chg: updated 01-font.c demo (@zpl-zak)
chg: updated docs

fix: crash when indexing out of bound vectors (iqe2iqm)
fix: editor using font faces 8,9,10 now
fix: large embedded textures were truncated (iqe2iqm)
fix: more accurate font_rect() bounding boxes (@zpl-zak)
fix: no repeating flags applied in embedded textures
fix: regression: invalid shift in 4-byte codepoints (string32)

brk: different font sizes within same line no longer supported
brk: x10 font faces, x6 font colors now