new i2c submenu containing master and slave entries
make the I2C slave code compile
since it is only a demonstration it can not be used for general tasks
reformatted source code to comply with Ethersex's style guide
the missing menuconfig files for i2c
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