Utils.notify should accept arbitrary hints

[ttoino]

Some non-standard hints (like value for making progress bars) are quite useful, but the current implementation of Utils.notify only allows known hints to be passed as arguments.

I suggest adding an additional hints argument, or just accepting arbitrary arguments in this function (though I personally prefer the first option).

[Aylur]

yeah, the hints are kind of hard coded, I'll try to refactor the notifications daemon, and Utils.notify to make it more flexible