1.12.1.9 "Can He Build It?"

This release has one feature removed and replaced with a newer, better, shinier feature. Ooh, shiny. The removed feature is the (clumsily written, by me) configuration for jpackage that was included in LWJGL3 build.gradle files. The replacement is that configuration for Construo is now included in LWJGL3 build.gradle files! Where jpackage would only build one binary for the current OS and architecture, Construo can build for other architectures than the one you're currently running on. It can also set the flag that Windows uses to prefer the discrete GPU on machines with both integrated and discrete graphics. The config is also a good amount cleaner. Huge thanks to @fourlastor for the PR and for writing Construo and its related tools!