/// \return the icon file name for the given action.
static docstring iconName(FuncRequest const & f, bool unknown);
/// \return the math icon name for the given command.
static docstring mathIcon(docstring const & c);
/// \return the icon file name for the given action.
static docstring iconName(FuncRequest const & f, bool unknown);
/// \return the math icon name for the given command.
static docstring mathIcon(docstring const & c);