Add a uwp-universal target to build all uwp arches at once
This is identical to how the cross-android-universal target works. Supported UWP arches are: x86, x86_64, arm64. This covers 100% of Windows 10 machines: https://docs.microsoft.com/en-us/windows/msix/package/device-architecture
Advantages are the same as Android:
- Most people will build apps that target multiple (or all) archs
- Easier to build and ship all arches at once
- Easier to download two tarballs rather than six
Also updated the README to mention it, and output a single tarball with both devel and runtime when building for UWP. Usage:
./cerbero-uninstalled -c config/cross-uwp-universal.cbc package gstreamer-1.0
Edited by Nirbheek Chauhan