moved Mesh:setWireframe to love.graphics.setWireframe (affects all draws until it's disabled.)

Wireframe mode should only be used for debugging: the wireframe lines behave differently than regular lines, their widths aren't affected by the graphics scale, and the mode isn't available on OpenGL ES.

src/modules/graphics/opengl/wrap_Graphics.h

@@ -85,6 +85,8 @@ int w_setPointStyle(lua_State *L);
 int w_getPointSize(lua_State *L);
 int w_getPointStyle(lua_State *L);
 int w_getMaxPointSize(lua_State *L);
+int w_setWireframe(lua_State *L);
+int w_isWireframe(lua_State *L);
 int w_newScreenshot(lua_State *L);
 int w_setCanvas(lua_State *L);
 int w_getCanvas(lua_State *L);