Pull up following revision(s) (requested by reinoud in ticket #89):
sys/arch/usermode/usermode/thunk.c: revision 1.81
sys/arch/usermode/target/i386/cpu_i386.c: revision 1.4
sys/arch/usermode/include/thunk.h: revision 1.61
sys/arch/usermode/include/intr.h: revision 1.9
sys/arch/usermode/dev/cpu.c: revision 1.70
sys/arch/usermode/dev/ttycons.c: revision 1.19
sys/arch/usermode/usermode/trap.c: revision 1.64
Implement signal forwarding to userland for usermode kernels. Especially
SIGFPE is important since the urkel shouldn't stop when a userland program
devides by zero!

(riz)