radius for the tabs //todo: core graphics geometry
Tab: round corners, close image highlighted (all configurable via appearance)
New: nonclosable tabs
Merge branch 'development'

Conflicts:
	QMBTabs Demo/QMBTabs Demo.xcodeproj/project.xcworkspace/xcuserdata/stefanmeschke.xcuserdatad/UserInterfaceState.xcuserstate