! (clean me) ui_box can respond to ui objects' events

! ui_box can respond to ui objects' events
+ events are stored in a dictionary within ui_box
+ event specifies the id when invoked
+ example: ui_box can pick up button_pressed

! messy, consider cleaning
! outside checks are awkward, rely on dict
! interior code could be cleaner

! ui objects can be set outside the ui_box
! example: give input box a string