Add title and icon properties to display_surface

[mateka]

It would be nice, if users of io2d could change title and icon of window with display_surface. That way, one could develop cross platform game in standard c++ (except for the sounds)!

[mikebmcl]

It may be possible that we can add a "suggested" title string without any problem. Implementations would receive the normative encouragement of "should" for situations where the output surface is capable of displaying such (i.e. in a windowing environment where the output is not fullscreen, which also raises the issue of having a "fullscreen" property of the same nature).

Indeed I explored this already and decided against it since for Win32 there would be a need to convert from a UTF-8 string to a UTF-16 string and there is no reliable standard way to do so currently. But I'll look into it again.

Icons are impossible in my opinion. Each windowing system has its own image format and size requirements for such a thing. If someone wants one, they can create an unmanaged output surface (i.e. their own window).

So for now it's a no on icons, but an open issue for window titles on platforms that have windows. I'm not ready to tackle the problem of switching between windowed and fullscreen just yet. Indeed, the original intent was to be completely unaware of the output medium. But at this point, I don't think that a "title" hint would be controversial.

-Mike