Added administration credentials

Admin resources can be secured via config.
Tenant Key Resource

Added ability to add and remove individual API keys for tenants.
Fix export

Make the export tenantless by using the base graph.
Use the latest version of Restlet.
Bump up the patch number.
Remove PartitionGraph

Remove the utilization of the TinkerPop PartitionGraph from the system.
The monolithic way in which it handles partitions does not work well
with the Collabinate architecture.
Fix concurrency issue

After removing synchronization on all public methods, there was an
issue with concurrency in the creation of entity vertices.
Add TenantID to all graph objects
Add Header Filter

Created a means to add headers to responses for metering, and to check
request headers for secret auth keys.
Add proper logging framework

Added SLF4J backed by Log4j2. This includes adding dependencies for the
LMAX disruptor, the JCL over slf4j bridge, and the restlet slf4j
extension. It also requires deletion of the existing log properties
files for jetty and log4j, and Maven exclusions for other logging impls.
Bump blueprints to 2.5.0-SNAPSHOT (using sonatype nexus repo) and force
use of Neo4j 1.9.5.
POM flesh out (for org, licenses, devs, etc.) and removal of
unnecessary scope tags.
Log concurrency errors instead of throwing