Adafruit-micropython-register

Fix README for new I2CDevice API. Make sure your [CircuitPython](https://github.com/adafruit/circuitpython) and libraries are up to date!

This changes the api of I2CDevice to make more sense when not providing the address:
* `readfrom_into` is now `read_into`
* `writeto` is not `write`

This is also updated to work with CircuitPython 0.9.4+ with the `nativeio` split.

This is a version of the Struct class that assumes only a single value is set/get and removes the need for explicit tuple packing/unpacking.

Improvements for RTC classes:
- Switch to `time.struct_time`.
- Fix up alarm register to take occurrence date and time plus a frequency.

New release with fix for I2C struct setter.