Add accountsservice files for Greeter use

[codygarver]

Ready for review but BLOCKED until it's confirmed this is what needs to be removed from Greeter, so the packages won't collide after build.

[decathorpe]

Why is this stuff getting moved from greeter to default settings?

[danirabbit]

@decathorpe To avoid the cyclical dependency situation we previously had with wingpanel-indicator-datetime that you had brought up ;)

[decathorpe]

@decathorpe To avoid the cyclical dependency situation we previously had with wingpanel-indicator-datetime that you had brought up ;)

:thinking: Wait ... but the greeter is the application actually providing these services. And now you're moving the files from greeter to default settings, with default settings mandating the use of greeter and the greeter depending on the default settings? The way I see it, you're introducing a circular dependency where there was none ...

[danirabbit]

@decathorpe No default settings isn't relying on the greeter. It's just providing an accountsservice extension. I think this extension probably needs to be namespaced in a different way to not reference the greeter since it'll be used by other OS components as well.

This way the date time indicator, the system settings pane, the greeter, and granite can all rely on default settings instead of pointing at each other

[tintou]

It doesn't collide with the greeter so it's safe to merge