Add multi-property serialization test.

Currently ignored until we figure out how to determine if something contains a multi-property.
started flusing out the BlueprintsTestSuite. The core to TinkerPop's consistency across vendors.
Features and Exceptions are now split with Exceptions being static classes and Features being instance classes that are dynamically configureable.
There is no more Feature interface as there is no more Featurable interface. All interfacing to Features is within the respective class.
Refactored tests to support declaring Features in tests as annotations.
Add a few comments.
remove checks for modifiers.
Refactor Feature convention tests to use parameters.
Refactored Features.

Moved all Features to Graph.  Restructured supports() function in Features.  Added FeatureSet marker interface.
Execute Gremlin Server failsafe tests independently of one another.
Added graph clear operations to GraphProvider in blueprints test suite.
Removed TestCase reference in imports.
Correct spelling in comment.
Allow for multiple FeatureRequirement annotations to be added to a test method.
Add some javadoc.
Add ID/label conversion for graphs.
Add a few vertex tests.
Validate compliance with Features in Blueprints Test Suite.
Removed the "query" Feature specification.

Without this capability you wouldn't be able to retrieve a vertex, so it kinda doesn't make sense.
Add test for empty graph construction.