Added unit tests for I2C_eeprom_cyclic_store and fixed a bug in the format() method and a possible bug with the "empty" marker literal being expressed as ~0UL (which isn't necessarily the same size as a uint32_t).
I2C_eeprom
* Added page sizes for larger memory sizes (still deriving from the ATxxCxxx datasheets)
I2C_eeprom_cyclic_store
* Add the cyclic store implementation.
* Add an example for cyclic use of EEPROM.
* Update keywords.txt for syntax highlighting the new class and it's members.
* Changed signature of begin() to match page size data type.
* Add getMetrics() to have an indication about lifetime
Tomas Hübner