Replace NullPointerException with UnsupportedOperationException
Change exception type to IllegalArgumentException
Merge branch 'multilang-nullpointerexception-fix' of https://github.com/forter/incubator-storm into STORM-396

Conflicts:
	storm-core/src/jvm/backtype/storm/multilang/ShellMsg.java

STORM-396: Replace NullPointerException with IllegalArgumentExeption
Added STORM-396 to changelog