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/libmodplug/libmodplug.toml

@@ -0,0 +1,25 @@
+[build]
+type = "autotools"
+
+[dependencies]
+runtime = [
+    "glibc",
+    "libcxx",
+]
+
+[[manual_sources]]
+file = "libmodplug-0.8.9.0-no-fast-math.patch"
+
+[package]
+description = "A MOD playing library"
+homepage = "http://modplug-xmms.sourceforge.net/"
+license = "LicenseRef-PublicDomain"
+name = "libmodplug"
+version = "0.8.9.0"
+
+[[source]]
+extract_dir = "$name-$version"
+post_extract = ["autoreconf -vfi"]
+sha256 = "md5:5ba16981e6515975e9a68a58d5ba69d1"
+url = "https://downloads.sourceforge.net/modplug-xmms/$name-$version.tar.gz"
+patches = [ "libmodplug-0.8.9.0-no-fast-math.patch" ]