Add Initial PID-controller for following a line
Add TASK's for PID and colordetection
Merge branch 'master' into Line_follower
Merge branch 'master' into Line_follower

Conflicts:
	main.c
Corrections so that code complies with nxtOSEK 2.18
Add support for registering colors and changing sensor.. NOT WORKING OPTIMALLY
Fix bug with sensors mode switch
Add functionality to disable linefollowing tasks
Merge branch 'master' into Line_follower

Conflicts:
	boot_programs/color_calibration/color_calibration.c
	boot_programs/color_measurement/color_measurement.c
	main.c
Merge branch 'master' into Line_follower
Fix main so that colorsensors will be set to the correct mode if line following is activated