Create dock tab bars externally.
Create tabbed widget tab bar externally.
Inherit DockTabBar from TabBar.
wz_tab_bar_remove_tab used the wrong event ID.
Added wz_widget_remove_child_widget.
Create dock tabs externally.
Create tab buttons externally.
Removed TabButton, use Button with a different draw style instead.
TabBar: use children member instead of a separate tab list.
Create tab pages externally.