Added support for several specific Canvas formats. Also added love.graphics.hasCanvasFormat.

The list includes RGBA with 4-bit components, RGBA with 10-bit R, G, and B components and a 2-bit alpha component, RGB with 9-bit RGB components and a 5-bit exponent component (for HDR rendering), and several more.

--HG--
branch : Canvas-formats

src/modules/graphics/opengl/wrap_Graphics.h

@@ -93,6 +93,7 @@ int w_getCanvas(lua_State *L);
 int w_setShader(lua_State *L);
 int w_getShader(lua_State *L);
 int w_isSupported(lua_State *L);
+int w_hasCanvasFormat(lua_State *L);
 int w_getRendererInfo(lua_State *L);
 int w_getSystemLimit(lua_State *L);
 int w_draw(lua_State *L);