Creates NavigationWidget.
Adds NavigationWidget to SceneView.
Reduces BrushStrokes initial radius: 2 cm -> .5 cm.
Remoned unnecessary BrushStrokesPicker listeners.
Minor fixes
Merge pull request #851 from RotaruDan/navigationPanel

Navigation widget
Merge pull request #854 from RotaruDan/drawFixes

Draw fixes
Bugfix
Reorder buttons always enabled
Updated Background selection layer
Meg
API changes
Added icons
Added switch to change between single and multiple selection