log messages should go to STDERR not STDOUT

[VladimirAlexiev]

Both of these

java -jar c:/prog/bin/owl-cli-snapshot.jar write IEC61970-600-2_CGMES_3_0_0_RDFS_501Ed2CD_EQ.ttl >  a.ttl
java -jar c:/prog/bin/owl-cli-snapshot.jar write IEC61970-600-2_CGMES_3_0_0_RDFS_501Ed2CD_EQ.ttl - >  a.ttl

cause the first output line to be

19:17:53.901 [main] DEBUG org.apache.jena.riot.system.stream.JenaIOEnvironment -- Failed to find configuration: location-mapping.ttl;location-mapping.rdf;etc/location-mapping.rdf;etc/location-mapping.ttl

making it invalid turtle.
(Even if you fix that particular problem, other log messages may mangle the output).

Invoking it like this (with explicit output file rather than STDOUT) doesn't cause the problem:

java -jar c:/prog/bin/owl-cli-snapshot.jar write IEC61970-600-2_CGMES_3_0_0_RDFS_501Ed2CD_EQ.ttl a.ttl