Controls renamed. Headers are created in XAML
Visibility of headers is controlled by Binding
Text of headers is bound
FontWeight is bound. Converter is added
Merge branch 'Sitrus2' into DUI-ArrangeMemberGroupsDependAvailability
Comments are provided and fixed
Merge branch 'Sitrus2' into DUI-ArrangeMemberGroupsDependAvailability
Check on null is added
Renamed Visibility properties and is{Members}empty properties
Merge pull request #46 from vmoyseenko/DUI-ArrangeMemberGroupsDependAvailability

Arrange member groups depending on their availability rework