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