Window configuration API

[blemelin]

Specific Demand

On the desktop platform, the tao::window::WindowBuilder is re-exported so the developer can configure how he wants his window to be (initial size, decorations, title, etc.). If I remember correctly, this was something that needed to be addressed in the future, since re-exporting APIs can cause problems in the long run.

Implement Suggestion

Right now, the DesktopConfig struct owns a WindowBuilder. I propose to replace it with a new WindowConfig struct, but before I submit a PR about that, I would like to know the maintainers vision.

EDIT : This fork has a rough implementation of what I think would be interesting. I made sure to prevent breaking changes by providing convenience methods.

[jkelleyrtp]

I think we want to adopt a more imperative API for configuring the window - I want to keep this open with the intention of keeping a WindowConfig struct.