Fix some typos in comments.

src/modules/graphics/opengl/Graphics.cpp

@@ -113,7 +113,7 @@ bool Graphics::setMode(int width, int height, bool fullscreen, bool vsync, int f
 	if (isCreated())
 		tempState = saveState();
 
-	// Unlad all volatile objects. These must be reloaded after
+	// Unload all volatile objects. These must be reloaded after
 	// the display mode change.
 	Volatile::unloadAll();
 
@@ -402,7 +402,7 @@ Canvas *Graphics::newCanvas(int width, int height)
 	Canvas *canvas = new Canvas(width, height);
 	GLenum err = canvas->getStatus();
 
-	// everything ok, reaturn canvas (early out)
+	// everything ok, return canvas (early out)
 	if (err == GL_FRAMEBUFFER_COMPLETE)
 		return canvas;
 

src/modules/graphics/opengl/Graphics.h

@@ -211,7 +211,7 @@ public:
 	int getModes(lua_State *L);
 
 	/**
-	 * Scissor defines a box such that everything outside that box is discared and not drawn.
+	 * Scissor defines a box such that everything outside that box is discarded and not drawn.
 	 * Scissoring is automatically enabled.
 	 * @param x The x-coordinate of the top-left corner.
 	 * @param y The y-coordinate of the top-left corner.

src/modules/graphics/opengl/VertexBuffer.h

@@ -36,7 +36,7 @@ namespace opengl
 {
 
 /**
- * VertexBuffer is an abstraction over VBOs (Vertex Buffer Objecys), which
+ * VertexBuffer is an abstraction over VBOs (Vertex Buffer Objects), which
  * falls back to regular vertex arrays if VBOs are not supported.
  *
  * This allows code to take advantage of VBOs where available, but still