Bugfix/package loading

Hi Joe,

The first commit is to address a problem/bug with googleChartsInit(....) in the use case when the argument is not NULL (loading individual charting packages from within the google charts API).

The second reworks some of the code to use google's [chartWrapper](https://developers.google.com/chart/interactive/docs/library_loading_enhancements?hl=de#chartwrapper) (smart enough to know what packages it needs and loads them dynamically) rather than a stand alone chart.  This should make googleChartsInit() obsolete.