I'm just getting started with a 3.6. According to the product description, there is a connection for a rtc battery. I bought a battery holder from PRJC. Is it a simple matter of wiring the + to vBat and the ground to GND? Do I need a crystal and, if I do, where does it go? Assuming that I get this hooked up properly, how do I read the rtc? Do I use an Adafruit library (1307? some other one?)?