control-dialog constructed in JS
construct ControlDialogInnerDiv, saving control items into attributes
ControlDialogElement, which holds reference to top-level div
simplifying initialization code for page
more simplification
remove HTML id attributes from ControlDialogElement
In ControlDialogElement use single self-closing tags where possible
fix error in circle dragging instructions setup
controlDialog.addFunctionInstructions
pass number (not position) as parameter to createNumberHandle