Checkboxradio: Do not update twice upon input vclick

Fixes gh-7378
Table: Remove superfluous and markup-whise invalid "locked" attribute

Fixes gh-7381
Table: Make sure column stays hidden if unchecked input is set unchecked
Table: Flatten out _refresh() and restrict colstart DOM manip to reflow
Table: Add _destroy()
Table: Test _destroy()
Table: Remove $.extend() and simplify _setHeaders()
Table: Record UI elements both when pre-rendered and not
Table: _destroy() re-format
Table: Implement _setOptions() for "disabled"