core/*: replace #if ENABLE_DEBUG with IS_ACTIVE
core/*: replace #if ENABLE_DEBUG with IS_ACTIVE

OlegHahm/RIOT,authmillenon/RIOT,miri64/RIOT,authmillenon/RIOT,kaspar030/RIOT,kYc0o/RIOT,ant9000/RIOT,kYc0o/RIOT,jasonatran/RIOT,jasonatran/RIOT,kYc0o/RIOT,kaspar030/RIOT,kYc0o/RIOT,kaspar030/RIOT,OlegHahm/RIOT,jasonatran/RIOT,OTAkeys/RIOT,miri64/RIOT,OTAkeys/RIOT,ant9000/RIOT,miri64/RIOT,authmillenon/RIOT,RIOT-OS/RIOT,OlegHahm/RIOT,kYc0o/RIOT,ant9000/RIOT,RIOT-OS/RIOT,ant9000/RIOT,kaspar030/RIOT,OlegHahm/RIOT,RIOT-OS/RIOT,OlegHahm/RIOT,ant9000/RIOT,jasonatran/RIOT,authmillenon/RIOT,OTAkeys/RIOT,RIOT-OS/RIOT,kaspar030/RIOT,authmillenon/RIOT,miri64/RIOT,authmillenon/RIOT,miri64/RIOT,jasonatran/RIOT,RIOT-OS/RIOT,OTAkeys/RIOT,OTAkeys/RIOT