Fixed syntax error resulting from copy/paste of artifact type.
Only call tzset if a timezone was passed in
One more check to not set TZ if empty string
Merge branch 'master' of https://github.com/sleuthkit/sleuthkit

Conflicts:
	bindings/java/jni/dataModel_SleuthkitJNI.cpp
	bindings/java/src/org/sleuthkit/datamodel/BlackboardArtifact.java