Change CMakeLists.txt to add 2d_game project, and added irrKlang to LIBS.

Added irrKlang.dll and ikpMP2.dll to dlls folder.  Added irrKlang as a
sub-folder under includes.  Added irrKlang.lib to lib folder.  At this point
running cmake gave an error it couldn't find source files under 2d_game.
Moved 2d_game source up one folder level, then cmake found the files.

src/7.in_practice/3.2d_game/shaders/sprite.vs

@@ -0,0 +1,14 @@
+#version 330 core
+layout (location = 0) in vec4 vertex; // <vec2 position, vec2 texCoords>
+
+out vec2 TexCoords;
+
+uniform mat4 model;
+// note that we're omitting the view matrix; the view never changes so we basically have an identity view matrix and can therefore omit it.
+uniform mat4 projection;
+
+void main()
+{
+    TexCoords = vertex.zw;
+    gl_Position = projection * model * vec4(vertex.xy, 0.0, 1.0);
+}