Clarify windows dependencies

Author: xlz

README.md

@@ -116,17 +116,12 @@ When you report USB issues, please attach relevant debug log from running the pr
 
     You can go back and forth between the SDK driver and the libusbK driver very quickly and easily with these steps.
 
-* Build libusb
+* Install libusb
 
-    Open a Git shell (GitHub for Windows), or any shell that has access to git.exe and msbuild.exe
-    ```
-    cd depends/
-    .\install_libusb_vs2013.cmd
-    ```
-    Or `install_libusb_vs2015.cmd`. If you see some errors, you can always open the cmd files and follow the git commands, and maybe build `libusb_201x.sln` with Visual Studio by hand. Building with "Win32" is not recommended as it results in lower performance.
+    Download the latest build (.7z file) from https://github.com/libusb/libusb/releases, and extract as `depends/libusb` (rename folder `libusb-1.x.y` to `libusb` if any).
 * Install TurboJPEG
 
-    Download from http://sourceforge.net/projects/libjpeg-turbo/files, extract it to `c:\libjpeg-turbo64` or `depends/libjpeg-turbo64`, or anywhere as specified by the environment variable `TurboJPEG_ROOT`.
+    Download the `-vc64.exe` installer from http://sourceforge.net/projects/libjpeg-turbo/files, extract it to `c:\libjpeg-turbo64` (the installer's default) or `depends/libjpeg-turbo64`, or anywhere as specified by the environment variable `TurboJPEG_ROOT`.
 * Install GLFW
 
     Download from http://www.glfw.org/download.html (64-bit), extract as `depends/glfw` (rename `glfw-3.x.x.bin.WIN64` to `glfw`), or anywhere as specified by the environment variable `GLFW_ROOT`.
@@ -146,6 +141,7 @@ When you report USB issues, please attach relevant debug log from running the pr
     cmake --build . --config RelWithDebInfo --target install
     ```
     Or `-G "Visual Studio 14 2015 Win64"`.
+    Or `-G "Visual Studio 16 2019"`.
 * Run the test program: `.\install\bin\Protonect.exe`, or start debugging in Visual Studio.
 * Test OpenNI2 (optional)