This setting doesn't work on most platforms
including some notification daemons on linux.
Where it does work I think it is bad behavior
to default overriding their defaults anyway.
It's most valuable use was likely win32
tray balloons which no longer exist.
This splits notifications up into multiple backends
currently only libnotify on unix and win8 toasts.
The win8 backend was originally written by @leeter
though heavily modified.