[UI-Util] Fixed resource leak in HandlerContributionItem

Signed-off-by: Stephan Wahlbrink <sw@wahlbrink.eu>
[UI-Components] Fixed enablement in handlers of history util on E-4

Signed-off-by: Stephan Wahlbrink <sw@wahlbrink.eu>
[Mvn] Updated build configuration
  - Updated to Tycho-0.18
  - Changed spec of encoding

Signed-off-by: Stephan Wahlbrink <sw@wahlbrink.eu>
[Releng] Fixed license url for features

Signed-off-by: Stephan Wahlbrink <sw@wahlbrink.eu>