Make notifications time zone agnostic

[bwernsman]

This is a PR to add an optional parameter to make local notifications timezone agnostic, if a notification is scheduled for 8 pm, it will trigger at 8 pm, no matter if you are in LA or NYC. I currently have it set as "isTimeZoneAgnostic", maybe "isTimeZoneIndependent", definitely open to feedback on this. I updated the docs as well, let me know if there is anything else.