I2C pins can now be mapped.
recover from out of bounds write on PWM duty.
use IO.sync to make sure writes end up at the right spot at the right time.
give the OS some time to load the driver.
Use Sync IO.
Cape include for the Pins/IO classes.
Extended documentation on Pin Mapper
added i2c to gemspec
first steps to i2c backend
fix some issues with i2c