libl4thread skeleton is introduced.

With this library, it is aimed at easing thread manipulation, utcb handling etc.

conts/libl4thread/src/thread.c

@@ -0,0 +1,10 @@
+/*
+ *
+ */
+
+#include <stdio.h>
+
+void l4thread_print(void)
+{
+	printf("Hello world from libl4thread!\n");
+}