Merge pull request #2377 from gdicristofaro/7576-useOsAccountId

bindings/java/doxygen/blackboard.dox

...ngs/java/src/org/sleuthkit/datamodel/AbstractContent.java

bindings/java/src/org/sleuthkit/datamodel/AbstractFile.java

bindings/java/src/org/sleuthkit/datamodel/Blackboard.java

.../java/src/org/sleuthkit/datamodel/BlackboardArtifact.java

bindings/java/src/org/sleuthkit/datamodel/Content.java

bindings/java/src/org/sleuthkit/datamodel/OsAccount.java

...s/java/src/org/sleuthkit/datamodel/OsAccountInstance.java

...gs/java/src/org/sleuthkit/datamodel/OsAccountManager.java

bindings/java/src/org/sleuthkit/datamodel/Report.java

bindings/java/test/org/sleuthkit/datamodel/ArtifactTest.java