FALCON-133 Upgrade to slf4j 1.7.5 and use SLF4J logger. Contributed by  Jean-Baptiste Onofré
Merge branch 'master' of https://git-wip-us.apache.org/repos/asf/incubator-falcon

Conflicts:
	common/src/main/java/org/apache/falcon/metadata/InstanceRelationshipGraphBuilder.java