AVS-Extrem-Board + new Drivers for the MSBA2-based Boards (LPC2387 CHIP) + Full abstracted I2C-Interface-Divers

. Support of the AVS-Extrem-Board.
. Porting from the CC1100-, SSP0-, and the SMB38-Drivers of the AVS-Extrem-Board in RIOT.
. Full abstracted I2C-Interface-Driver for the LPC2387 Chip.
. Driver for the SRF02 ultrasonic sensor.
. Driver for the SRF08 ultrasonic sensor.
. Driver for the LM75A temperature sensor demonstrating the use of the i2c-interface and the external interrupts