Allow "random" optional parameters in url

[RodolpheGohard]

I need to use optional parameters in my URLs, such as:

example.org/#search?text=optional%20params&orderBy=DATE

here, either text or orderBy are optional and can be independently present. So that won't allow constructions like search/:text/:orderBy.

And the parameters are absent from $state.params or $stateParams.

I have to use $locationChangeSuccess events combined $location.search() and
it's not practical at all. Partly because it fires before state changes.

It would be neat if there were an event like $stateUpdated, and also if
optional parameters were included in $stateParams.
Or maybe there's already some mechanism for this in UI router, if so please
tell me.

[christopherthielen]

Optional params were added in 0.2.11 with little fanfare.
#1032