message: readme: update example and notice on API changes to grove and i2clcd
diff: @@ -30,7 +30,7 @@ sensors and actuators and provide feedback on interface design.
  A sensor/actuator is expected to work as such (here is the MMA7660 accelerometer API):
  ```C++
  // Instantiate an MMA7660 on I2C bus 0
  - upm::MMA7660 *accel = new upm::MMA7660(MMA7660_I2C_BUS,
  + upm::MMA7660 *accel = new upm::MMA7660(MMA7660_DEFAULT_I2C_BUS,
  MMA7660_DEFAULT_I2C_ADDR);
  // place device in standby mode so we can write registers
  @@ -136,7 +136,8 @@ our API in a way that will break backwards compatibility. If you find yourself
  unable to compile code that was working fine before a library update, make sure
  you check the [API changes](docs/apichanges.md) section first.
  -**NOTE** - Our **C++ header files** changed extension from *.h* to *.hpp*!
  +**NOTE** - Several important API changes are currently underway for some of our
  +widely used libraries including `libupm-grove` and `libupm-i2clcd`!
  ### Changelog
  Version changelog [here](docs/changelog.md).
  