NEW: Support for PCA9632

Now I try again, with only the files in question.
Added: support for PCA9632 (NXP 4-bit LED dimmer I2C-chip)

Depends on I2C-Generic and supports 
* Setting 4 LEDs individual with an 8-bit PWM value
* Setting group dimming
* Setting group blinking incl. setting the frequency and duty cycle
* Software resetting the chip
* EMCD