Multiedit tasks - bad initial values / #2744

There are some bad inistial values in multiedit tasks:

1. if one of tasks was assigned to "for milestone" or "resolved in" which is not open or blocked (closed, done?, approved), then those combos displays none instead milestones they belongs to - I think we do not check in SQL query closed milestones (and approved, done).
2. when edited tasks have different status, then combo displays status new instead of --keep different--

Please check the logic of this operations.
I checked some other options and they looks good, but maybe I missed some options.