Make raise_exception use "error" command
Make raise_exception use "error" command

It used to use "log", but that doesn't seem right, since the multilang protocol has a specific "error" command for error.  

See apache/storm@55289623d4
petchat/streamparse,msmakhlouf/streamparse,scrapinghub/streamparse,crohling/streamparse,eric7j/streamparse,msmakhlouf/streamparse,scrapinghub/streamparse,eric7j/streamparse,petchat/streamparse,codywilbourn/streamparse,Parsely/streamparse,msmakhlouf/streamparse,codywilbourn/streamparse,scrapinghub/streamparse,hodgesds/streamparse,msmakhlouf/streamparse,petchat/streamparse,Parsely/streamparse,petchat/streamparse,msmakhlouf/streamparse,hodgesds/streamparse,scrapinghub/streamparse,crohling/streamparse,scrapinghub/streamparse,phanib4u/streamparse,petchat/streamparse,phanib4u/streamparse