Added first part of extended ipc support.

- Extended ipc tests
- Need to copy from ktcb-to-ktcb instead of ktcb-to-user
- Need to check flags of both ipc parties before ipc copy type.

tasks/test0/include/tests.h

@@ -14,6 +14,7 @@
 extern pid_t parent_of_all;
 
 void ipc_full_test(void);
+void ipc_extended_test(void);
 
 int shmtest(void);
 int forktest(void);