make glfw work on Windows

examples/tetris/README.md

@@ -1 +1,12 @@
 <img src='https://raw.githubusercontent.com/vlang/v/master/examples/tetris/screenshot.png' width=300>
+
+Tetris has a temporary dependency on GLFW. 
+
+## macOS
+`brew install glfw` 
+ 
+## Ubuntu 
+sudo apt install libglfw3 libglfw3-dev 
+
+## Windows 
+Copy `thirdparty/glfw/glfw3.dll` to this directory. 

vlib/glfw/glfw.v

@@ -5,23 +5,19 @@
 module glfw
 
 #flag -I @VROOT/thirdparty/glfw 
-
+#flag -L @VROOT/thirdparty/glfw 
-#flag windows @VROOT/thirdparty/glfw/libglfw3.a 
 
 // Debugging a custom build
-#flag darwin -L/var/tmp/glfw/src/
+//-#flag darwin -L/var/tmp/glfw/src/
+
 #flag darwin -lglfw
 #flag linux -lglfw
-#flag windows -I/usr/local/Cellar/glfw/3.2.1/include/
+#flag windows -lglfw3 
-// #include <glad/glad.h> // !gen.go include GLFW.v
 #include <GLFW/glfw3.h>
 // #flag darwin -framework Carbon
 // #flag darwin -framework Cocoa
 // #flag darwin -framework CoreVideo
 // #flag darwin -framework IOKit
-// struct C.GL
-// @GLFWwindow* C.glfwCreateWindow
-// #int gconst_init = 0;
 const (
 	RESIZABLE = 1
 	DECORATED = 2