Save/restore window position [BiteSize]

[Jason Gerard DeRose]

I pinged tedg about this, and I guess it is now the app's responsibility to save and restore the window position (probably dates me a bit, hehe).

We want to know if the window was maximized/um-maximized, and what the um-maximized size and position was.

I struggled a bit to find how to do this correctly, but for someone who knows, this is a tiny change I imagine.

Note that as this is really machine-specific state, we're not going to sync this through CouchDB (plus, we don't want to wait for dc3/desktopcouch to start to correctly position the window).

I supposed dconf should be used, although my gut reaction is a JSON file in ~/.config/APP/state.json or some such as this is not something we need change signals for... just save it at app shutdown.

Also note that we're name-spacing based on the value of BaseUI.app, which will be something like 'novacut', or 'dmedia', or 'yourcoolapp'.