LM75A-Project + SRF02 & SRF08 ultrasonic senors projects + LP2387-external-interrupts Project + updated test_shell-proect

lm75A-temp-sensor project: demonstrating the use of the LM75A- and the I2C-drivers.
srf02-ultrasonic-sensor project: demonstrating the application of the SRF02 ultrasonic sensor driver.
srf08-ultrasonic-sensor project: illustrating the use of the SRF08 ultrasonic sensor driver and the simultaneous capture of multiple echoes resp. objects.
lpc2387-external-interrupts project: realizing the set up and the use of arbitrary pins as external interrupt source in the LPC2387 chip.