Visual editor jtable additions

fixes some typos
add Mac-specific symbols (⌘) and tags ("cmd" translates to "meta)
make the context tags nicer (include the "×" to remove them into the RoundedBorder)
focus handling: Shift-Tab/Tab in the bindings table move focus to previous/next component
hiding restore/apply buttons if editor is embedded elsewhere
revised modelToConfig() to use new InputTriggerConfig methods
moved demo to separate class VisualEditorPanelDemo

scijava / ui-behaviour