Dropped rootWindow.showAll

Used settings.showAll instead.
[sailfish] Removed unused parameter
[harmattan] Removed unused parameter
Used value from settings for showAll in initState
Don't cache showAll in MenuItem and use settings as reference
Merge branch 'show-all' of git://github.com/michael-k/ttrss into michael-k-show-all
Merge branch 'master' of github.com:cnlpete/ttrss
Merge branch 'master' of github.com:cnlpete/ttrss

Conflicts:
	qml/ttrss/models/FeedItemModel.qml