Added Font:setFallbacks(otherfont, ...). Resolves issue #1041.

Note that general font metrics are largely still based on the original (non-fallback) font, whereas glyph sizes are based on the fallback fonts when those are used to get the glyph.

src/modules/graphics/opengl/wrap_Font.h

@@ -44,6 +44,7 @@ int w_Font_getAscent(lua_State *L);
 int w_Font_getDescent(lua_State *L);
 int w_Font_getBaseline(lua_State *L);
 int w_Font_hasGlyphs(lua_State *L);
+int w_Font_setFallbacks(lua_State *L);
 extern "C" int luaopen_font(lua_State *L);
 
 } // opengl