GraphBackendDiscoveryService as it relates to the graph directly.  The
code was inactive but remains commented as a reminder for future work.

org.apache.hadoop.metadata.discovery.GraphBackedDiscoveryService.  Will
need additional clean up, but the functionality remains the same.

Adds Apache License Headers, enables rat-check, find-bugs and checkstyle plugins. Contributed by Venkatesh Seetharam

viewing of the output format.  

some additional logging.  Added a requestId element to the returned
JSON.

text search as before, the other accepts a GUID and will walk the graph
using the Edges specified in the query.  API call samples are in
MetadataDiscoveryResource.java.

search code committed last night.

they are not services and made more sense with simpler, shorter names

ServiceInitializer and Services collection no longer exist and have been
replaced by Guice dependency injection.
Added comments and improved testability.
Maven verify now runs - almost ready for CI (issues with keytool maven
plugin)

properties file

and the test parses the GUID as expected

with integration tests (specifically the metadata.keystore file &
keystore plugin), but int tests are otherwise loading Guice
dependency-injected instances correctly.

similar and could easily be performed inside of the repository module

todo: add more parser functionality around astnode specifically around
partitions, drops, updates and alters

Repository systems

Initial project code with maven modules and basic repository code. Contributed by Venkatesh Seetharam