Simplified LibraryTreeItemsHostVisibilityConverter
Children are collapsed during expanding of parent
Merge branch 'Sitrus2' into DUI-MarginsFix
Reverted missed tests
EOF on new line
Curly brackets are added
Merge pull request #229 from vmoyseenko/DUI-MarginsFix

Margins change
Merge pull request #240 from vmoyseenko/DUI-CollapseNextLevelItems

Children should be collapsed during expanding of parent
Merge branch 'Sitrus2' into DUI-NoRightSecondaryH