Add new packages and build scripts for various libraries

- Added Nuklear GUI library with build script and configuration.
- Introduced OpenH264 encoder/decoder with build configuration.
- Added PortAudio library for audio I/O with custom build script.
- Included Python Execnet for multi-Python deployment.
- Added Pytest Xdist plugin for distributed testing.
- Introduced Shaderc for shader compilation tools.
- Added Snappy compression library with necessary patches and configuration.
- Included SoundTouch audio processing library with build configuration.
- Added SRT library for secure reliable transport.
- Introduced VapourSynth video processing framework with configuration.
- Added Vid.stab for video stabilization.
- Included WebRTC Audio Processing library with build configuration.
- Added X264 video encoding library with patches for POSIX compliance.
- Introduced X265 video encoder with build configuration.
- Added XKeyboard Config for X keyboard configuration files.
- Included Xorg XKBComp for keyboard description compilation.
- Added Xvidcore MPEG-4 video codec library with configuration.
- Introduced ZeroMQ messaging system with patches and build configuration.
- Added Zimg library for scaling and colorspace conversion.

extra/libxkbcommon/build.sh

@@ -0,0 +1,80 @@
+#!/bin/sh
+set -eu
+
+makei() {
+  echo "==> Running: make DESTDIR=\"$pkgdir\" install $*"
+  make DESTDIR="$pkgdir" install "$@"
+}
+
+mesoni() {
+  echo "==> Running: meson install --destdir \"$pkgdir\" $*"
+  meson install --destdir "$pkgdir" "$@"
+}
+
+cmakei() {
+  echo "==> Running: cmake --install $*"
+  DESTDIR="$pkgdir" cmake --install "$@"
+}
+
+starmove() {
+  [ "$#" -ge 1 ] || {
+    echo "starmove: requires at least one path pattern" >&2
+    return 1
+  }
+  [ "${DEPOT_OUTPUT_NAME:-}" != "" ] || {
+    echo "starmove: DEPOT_OUTPUT_NAME is not set" >&2
+    return 1
+  }
+  haul "$DEPOT_OUTPUT_NAME" "$@"
+}
+
+depot_starbuild_sync_srcdir() {
+  workdir=${DEPOT_STARBUILD_WORKDIR:?}
+  compat_root="$workdir/.depot-starbuild"
+  mkdir -p "$compat_root/packages"
+  for entry in "$workdir"/* "$workdir"/.[!.]* "$workdir"/..?*; do
+    [ -e "$entry" ] || [ -L "$entry" ] || continue
+    base=$(basename "$entry")
+    [ "$base" = ".depot-starbuild" ] && continue
+    [ "$base" = "packages" ] && continue
+    ln -snf "$entry" "$compat_root/$base"
+  done
+  mkdir -p "$compat_root/packages/libxkbcommon/"
+  ln -snf "${DEPOT_PRIMARY_DESTDIR:-$DESTDIR}" "$compat_root/packages/libxkbcommon/files"
+  mkdir -p "$compat_root/packages/libxkbcommon-x11/"
+  ln -snf "$(subdestdir 'libxkbcommon-x11')" "$compat_root/packages/libxkbcommon-x11/files"
+  srcdir="$compat_root"
+  export srcdir
+}
+
+depot_starbuild_setup_env() {
+  package_name=$1
+  package_version='1.12.3'
+  pkgdir=${DESTDIR:?}
+  export package_name package_version pkgdir
+  LANG=C
+  LC_ALL=C
+  export LANG LC_ALL
+  depot_starbuild_sync_srcdir
+}
+
+depot_build() {
+  depot_starbuild_setup_env 'libxkbcommon'
+      # Add your commands here
+      meson setup build -Dprefix=/usr --buildtype=release --libdir="/usr/lib"
+      ninja -C build
+      # Add your commands here
+}
+
+depot_install() {
+  depot_starbuild_setup_env 'libxkbcommon'
+      mesoni -C build
+}
+
+depot_install_libxkbcommon_x11() {
+  depot_starbuild_setup_env 'libxkbcommon-x11'
+      starmove usr/lib/*x11*
+      starmove usr/lib/pkgconfig/*x11*
+      starmove usr/include/xkbcommon/*x11*
+      starmove usr/share/man/man1/*x11*
+}

extra/libxkbcommon/libxkbcommon.toml

@@ -0,0 +1,42 @@
+[build]
+type = "custom"
+
+[dependencies]
+build = [
+    "meson",
+    "wayland",
+    "wayland-protocols",
+    "xkeyboard-config",
+    "xorgproto",
+    "libxcb",
+    "git",
+    "graphviz",
+    "doxygen"    
+]
+runtime = [ "glibc", "libxml215", "xkeyboard-config" ]
+optional = [ "wayland", "libxkbcommon-x11" ]
+
+[package]
+description = "Keymap handling library for toolkits and window systems"
+homepage = "https://github.com/xkbcommon/libxkbcommon.git"
+license = "MIT"
+name = "libxkbcommon"
+version = "1.13.1"
+
+[package_dependencies.libxkbcommon-x11]
+runtime = [
+    "glibc",
+    "libxcb",
+    "libxkbcommon",
+]
+
+[[packages]]
+description = "Keyboard handling library using XKB data for X11 XCB clients"
+homepage = "https://xkbcommon.org/"
+license = "MIT"
+name = "libxkbcommon-x11"
+version = "1.13.1"
+
+[[source]]
+extract_dir = "libxkbcommon"
+url = "https://github.com/xkbcommon/libxkbcommon.git#xkbcommon-$version"