###### Motivation for this change
Update to latest upstream version
###### Things done
* [ ] Tested using sandboxing ([nix.useSandbox](http://nixos.org/nixos/manual/options.html#opt-nix.useSandbox) on NixOS, or option `sandbox` in [`nix.conf`](http://nixos.org/nix/manual/#sec-conf-file) on non-NixOS linux)
* Built on platform(s)
* [x] NixOS
* [ ] macOS
* [ ] other Linux distributions
* [ ] Tested via one or more NixOS test(s) if existing and applicable for the change (look inside [nixos/tests](https://github.com/NixOS/nixpkgs/blob/master/nixos/tests))
* [ ] Tested compilation of all pkgs that depend on this change using `nix-shell -p nix-review --run "nix-review wip"`
* [x] Tested execution of all binary files (usually in `./result/bin/`)
* [ ] Determined the impact on package closure size (by running `nix path-info -S` before and after)
* [ ] Ensured that relevant documentation is up to date
* [x] Fits [CONTRIBUTING.md](https://github.com/NixOS/nixpkgs/blob/master/.github/CONTRIBUTING.md).
###### Notify maintainers
cc @blitz @Ma27 @tfc @worldofpeace
- Begin a new chapter "GPU Acceleration", this should also cover
VA-API, OpenGL, Vulkan, etc.
- Add a general blurb about OpenCL and how to check whether OpenCL
devices are found.
- Add a section about enabling OpenCL for AMD GPUs specifically.
This utility reports information about AMD GPUs that are supported by
the ROCm stack. It also exposes functionality for clock and
temperature management.
* Update to 4.4.2
4.4.0 increased the ZScript version number, GZDoom 4.4.1 and 4.4.2 have some bugfixes.
* Fix bad checksum
Old hash was done without `--unpack` option, resulting in a mismatch.
* Fetch submodules
This fixes the issue with `zmusic` not being brought in as a dependency.
* Add zmusic derivation
Since zmusic isn't actually a submodule, we have to derive it ourselves and pass it as a buildInput.
* Semicolon.
* Semicolon in the *right* place this time.
* Merge the zmusic source into the gzdoom source.
Apparently this is how they expect zmusic to be added. Why this isn't a submodule, I don't know.
* Fix bad path editing
Credit to Open Skies for fixing this. Turns out the paths edited in the `gzdoom` derivation were for zmusic, which needs these edits to be made so that it looks in nix-friendly places for its stuff.