SI-5227 make fsc notify its client upon compiler crash
SI-5227 make fsc notify its client upon compiler crash

Fsc shoudln't just write to its own stderr when a major compiler crash
happens, it should also send an error to the client (`scala -e` for
example).

Otherwise the client thinks everything went fine (silence == success)
and tries to run something, crashes too, and displays only its own
error, not the original one.

jvican/scala,shimib/scala,slothspot/scala,felixmulder/scala,jvican/scala,felixmulder/scala,scala/scala,scala/scala,slothspot/scala,scala/scala,shimib/scala,felixmulder/scala,felixmulder/scala,shimib/scala,felixmulder/scala,martijnhoekstra/scala,martijnhoekstra/scala,scala/scala,lrytz/scala,felixmulder/scala,lrytz/scala,martijnhoekstra/scala,jvican/scala,martijnhoekstra/scala,scala/scala,slothspot/scala,jvican/scala,shimib/scala,shimib/scala,slothspot/scala,shimib/scala,scala/scala,jvican/scala,martijnhoekstra/scala,martijnhoekstra/scala,jvican/scala,lrytz/scala,lrytz/scala,slothspot/scala,jvican/scala,lrytz/scala,lrytz/scala,felixmulder/scala,slothspot/scala,slothspot/scala