I installed this i2c_tools package from the repo, but I'm not sure I needed to.
i2c-tools works out of the box and relies on smbus c functions, but the c program reading/writing through the hardware i2c doesn't see the smbus functions in the #include <linux/i2c.h> or #include <linux/i2c-dev.h> included with the vanilla install. When I built a c program with the i2c_smbus_read_word_data function I would get a warning: implicit declaration of function "i2c_smbus_read_word_data". I think it means, that while the library that is built on the device knows these functions (again i2c-tools works and uses them) it isn't declared (or made public) through the .h files pointed to in eclipse. Changing the .h in eclipse to declare the smbus functions and defines (using any other i2c-dev.h from a different linux distro should do) allowed me to use the regular i2c_smbus . . . function calls and use the more prevalent help to get all my i2c connections working.