core/clist: add clist_count()
core/clist: add clist_count()

kYc0o/RIOT,lazytech-org/RIOT,RIOT-OS/RIOT,basilfx/RIOT,OlegHahm/RIOT,mfrey/RIOT,OTAkeys/RIOT,OlegHahm/RIOT,aeneby/RIOT,authmillenon/RIOT,basilfx/RIOT,authmillenon/RIOT,jasonatran/RIOT,OlegHahm/RIOT,authmillenon/RIOT,josephnoir/RIOT,aeneby/RIOT,lazytech-org/RIOT,RIOT-OS/RIOT,mtausig/RIOT,smlng/RIOT,smlng/RIOT,kYc0o/RIOT,miri64/RIOT,toonst/RIOT,OTAkeys/RIOT,cladmi/RIOT,yogo1212/RIOT,OTAkeys/RIOT,RIOT-OS/RIOT,x3ro/RIOT,jasonatran/RIOT,rfuentess/RIOT,cladmi/RIOT,toonst/RIOT,kYc0o/RIOT,smlng/RIOT,miri64/RIOT,mtausig/RIOT,cladmi/RIOT,OlegHahm/RIOT,x3ro/RIOT,basilfx/RIOT,ant9000/RIOT,toonst/RIOT,RIOT-OS/RIOT,authmillenon/RIOT,kaspar030/RIOT,mtausig/RIOT,rfuentess/RIOT,authmillenon/RIOT,mfrey/RIOT,yogo1212/RIOT,aeneby/RIOT,jasonatran/RIOT,x3ro/RIOT,OlegHahm/RIOT,yogo1212/RIOT,authmillenon/RIOT,miri64/RIOT,aeneby/RIOT,basilfx/RIOT,ant9000/RIOT,kaspar030/RIOT,rfuentess/RIOT,kaspar030/RIOT,kaspar030/RIOT,RIOT-OS/RIOT,jasonatran/RIOT,mfrey/RIOT,josephnoir/RIOT,lazytech-org/RIOT,OTAkeys/RIOT,kYc0o/RIOT,toonst/RIOT,josephnoir/RIOT,yogo1212/RIOT,kYc0o/RIOT,ant9000/RIOT,jasonatran/RIOT,mtausig/RIOT,OTAkeys/RIOT,yogo1212/RIOT,kaspar030/RIOT,smlng/RIOT,smlng/RIOT,mfrey/RIOT,miri64/RIOT,cladmi/RIOT,ant9000/RIOT,x3ro/RIOT,lazytech-org/RIOT,rfuentess/RIOT,miri64/RIOT,toonst/RIOT,basilfx/RIOT,josephnoir/RIOT,ant9000/RIOT,lazytech-org/RIOT,rfuentess/RIOT,x3ro/RIOT,mfrey/RIOT,mtausig/RIOT,josephnoir/RIOT,yogo1212/RIOT,cladmi/RIOT,aeneby/RIOT