Open new window offset from last focused window (#573)

[albinekb]

When clicking "new window" in the dock, no window is focused, thus opening it at the same position as the old window.

This PR will make it use our awesome getLastFocusedWindow so that it will work as expected even if no window is focused.

Fixes #573

[MrRio]

Looking good, one small tweak if possible, when you do "New Window" multiple times in a row (strange use case I realise) it keeps opening in the same spot. The focused window needs to be set to the newly opened one.

[lordgiotto]

We could simply trigger win.focus() after window creation (regardless this PR): it's an intuitive behaviour in my opinion, and could fix this issue.

[MrRio]

@lordgiotto yeah agreed

[lordgiotto]

@MrRio We should make another PR to keep commit history clean? Or we could append this modification to this PR?
Eventually I can do the PR if you wish.

[lordgiotto]

Ok, I just realized that's not the problem: on window creation win.show() is triggered, so it gives focus to the window automatically. Therefore the cause of the issue pointed out by @MrRio is somewhere else: maybe simply a timing issue?

[MrRio]

I've fixed it in another PR :)

[MrRio]

The issue is that the onFocus event doesn't fire, which doesn't update the time used by getLastFocusedWindow

[lordgiotto]

Yeah, it's called on init rpc event, that triggers after session is created and everything in borwserWindow is initialized. I'll comment on your new PR thought, i've a suggestion about encapsulation :)

[MrRio]

Fixed in #581