0004793: Some filters are lacking the [none] selection
Description
If I want to filter issues that are not yet attached to a product version I have a hard time finding these...
It would be nice if the filters for:
product build
product version
fixed in version
would display [none] in addition to [any] and allow me to filter by issues that are not assigned.
Additional Information
It looks like the filter for 'fixed in version' already has this behaviour, it displays two blank lines after the [any] entry. The filter results (count) are different depending on which blank line I select for filtering. Maybe you should just name the first blank line [none] :-)
