Merge pull request #447 from OlegHahm/thread_include

added thread.h include (necessary since 227c8471).

core/mutex.c

@@ -27,6 +27,7 @@
 #include "tcb.h"
 #include "kernel.h"
 #include "sched.h"
+#include "thread.h"
 #include "irq.h"
 
 #include "debug.h"

core/sched.c

@@ -27,6 +27,7 @@
 #include <kernel_internal.h>
 #include <clist.h>
 #include <bitarithm.h>
+#include "thread.h"
 
 #if SCHEDSTATISTICS
 #include "hwtimer.h"