when we get a 40* error from server about private storage, it doesn't mean server doesn't support it.

[shivan] show nothing in status combobox when status is not unified for all globaly sync'ed accounts. see #3489

change global status when we set it through systray menu, even if one account already has this status. see #3489

Cleanup for chat_control_popup. Rename 'Show Frieds' to 'Show Contacts'. Show icon and disable invite functionality for zeroconf contacts.

NonModalConfirmationDialog and ConfirmationDialognow automaticaly close window on ok or cancel. fixes #3486

Add global search to history_viewer. Minor GUI improvements. Fix nasty bug: history_window was adding unexisting jids to logs.db, when it was tried to view their history.