hw: cancel waiting for IPC requests

ref #899
hw: kill signal receivers

ref #899
hw: fix bug in Kernel::yield_thread

ref #899
launchpad: remove '\n' from PERR message

ref #899
hw: enable multiple compilation units in kernel

ref #899
hw: enable verbose thread starts

ref #899
hw: fix bug in Kernel::Thread::resume

ref #899
hw: return error code on IPC replies

ref #899
base: fix bug in Object_pool::first_locked

fix #899