* Added ui.components.textboxes.DefaultTextBox
* All events are now handled by ui.internals.event_types
* All UIComponents keep track of the events they are listening to
* All UIComponents stop listening to their events when their visibility is set to false, and start listening when their
        visibility is set to true
* TextBox now can properly gain an lose focus
* TextBox can be typed in when it has focus.
* TextBox can delete the last character using backspace.
* TextBox still has no Caret support or select support.
* Added ui.uicomponent.UIComponent.setVisibilityRecursive as well as ui.uicomponent.UIContainer.setVisibilityRecursive.  Recommend
        using these rather than the regular setVisibility in most cases.