Adding explicit call of Event::Handler constructor in TWI::Driver.
Cleaning up ADXL345 driver output format and removing unnecessary include.
Major refactoring and improvement of HMC5883L device driver.

1. Add support device identity checking.
2. Fix error on reading register file.
3. Add scaling to milli-gauss.
4. Check for overflow.
Cleanup.
Testing CC1101 device driver build.