Changed buttons to default to a darker shade of grey.
'create_context_menu' now sets the buttons to white.
Element's '_remove_child' function now checks if the child to be removed even exists in that element.
Element's 'update_for_mouse_move' now checks if it's been packed yet.
Element's 'update_for_mouse_release' now checks if it's been packed yet.
Fixed bug with InputBox's test with context menus.
Button's now only triggerSubmit when clicked with the left mouse button.
Tooltips now try to fit inside of the screen when possible.