`If-None-Match` support, Dependency updates

• Adds If-None-Match support for non-State document storage (credit: @brianjmiller)
• Adds OWASP dependency checker during build (credit: @mikemcgowan)
• Bumps junit, jackson-databind, jackson-annotations, jackson-core, jetty-client, jetty-servlet, lombok dependencies (credit: @mikemcgowan)
• Minor changes to README, test ids, etc.

Attachment Support, Bump Jackson Dependency

• Fleshes out Attachment support for both sending/receiving attachments with statements using the multipart functionality as described in the specification (credit: @FishHooks @tseabrooks)
• Bumps Jackson dependency version to 2.7.4 (credit: @gomezgoiri)

Target JDK8, update to Jetty 9, Improve RemoteLRS HTTP Client Interface

This release bumps the major version because we now target the Java 8 JDK and require a new major version of Jetty. The public interface should be backwards compatible fully, but the dependency changes necessitated a major version bump.

Credit @gomezgoiri for significant work on the Jetty 9 transition.

Add long-fill-in Interaction Type

• Adds code to recognize the "long-fill-in" interaction type. (credit @davidells)

Various Additions and Fixes

• Updated Lombok dependency in anticipation of moving to JDK8 (credit @gomezgoiri)
• Add retrieveActivity and retrievePerson methods of LRS objects
• Add populateWithAvailableLanguages method to LanguageMaps (credit @dacdave)
• Fix Statement construction for non-base properties (credit @okabe-is)

Document Update Methods

• Added methods for updating documents: Agent Profile, Activity Profile (@dacdave) and State
• Updated Travis CI to point to new dedicated account

LRS Interface Overhaul

NOTE: Backwards Incompatible Changes!

This release completely breaks the existing LRS interface and now provides significant more functionality while providing better error handling and response resolution. This brings the library inline with the other more recent libraries' architecture. It provides a set of objects that represent the response from an LRS during calls to it with a success property (among others) that gives a better indication of what happened during request processing. Given this is the design used in several of the other libraries I don't anticipate another significant backwards incompatible redesign.

Various bug fixes were applied as well.