Add requisite dependencies for building crates on Windows

[ecstatic-morse]

This is meant to be an ongoing tracking issue. If anyone observes a crate failing to build due to a missing dependency, post it here.

Libraries should be added to vc-packages.txt and will be automatically installed via vcpkg. Executables should be installed via choco-packages.txt.

• [ ] freetype (required by jjjjw.rust_elmish_rocket)
• [ ] pkgconfig (required by curl-sys)
• [ ] libgit2
• [ ] libmysql (mysqlclient required by astaupb.wp_posts_api)
• [ ] libsndfile
• [ ] libusb (required by libusb-sys)
• [ ] opencl (required by ocl)
• [ ] portaudio (required by weresocool-0.1.0)
• [ ] SDL2-image (required by ruscur.phase)
• [ ] python (3, named python.exe) (required by shaderc-sys)
• [x] clang (required by wepoll-sys-1.0.3)
• [x] curl
• [x] cmake (required by shaderc-sys)
• [x] libsodium
• [x] libssh2
• [x] libpq
• [x] ninja (required by shaderc-sys)
• [x] openal (required by Tethik.beepr)
• [x] openssl (required by rust-openssl)
• [x] portmidi (required by diaschisma.mimi)
• [x] sdl2 (required by Ade-AWD.Foxxy)
• [x] sqlite3

[ecstatic-morse]

I found some candidates by looking at the reverse dependencies of vcpkg.