new ECMD to list the files stored in I2C EEPROM file system
reformat files to comply with Ethersex's style guide
multi-line output of ECMD "free" using ECMD_AGAIN to fit in smaller buffers
reformat file to comply with Ethersex's style guide
save four bytes of PROGMEM
implement vfs_unlink for I2C EEPROM
new ECMD "rm" to remove files
Merge pull request #245 from eku/i2c

new ECMDs for EEPROM file system