added the concept of Thing and anything can have a property with recrussion for meta properties.
first draft of Features using Feature interface and defender methods in Java8.
first draft of Features using Feature interface and defender methods in Java8.
Merge remote-tracking branch 'origin/master'
Add "accept" argument to eval to allow serialization selections.
Add GremlinGroovyScriptEngine code.

This is basically the same as the previous implementation in 2.x.
Remove Rexster module for now.
renamed the gremlin-server.sh to just gremlin.sh
Make the OpProcessor and GremlinExecutor thread-safe for creation.
removed the default wrappers for graph-centric computing. TinkerGraph implements this natively and any non-trivial implementation of GraphComputing should have their own implementation of these interfaces (no wrappers needed).
added hidden properties to Blueprints API via Property.Key.hidden(blah) using %$% prefix API-enforced convention. Random other tweaks here and there.
use newly added Tokens to get the Gremlin version.
Updated Settings to handle scriptengine configuration.
Got rid of singletons.
ScriptEngine now supports imports through configuration in yaml file.
Add REPL history, autocomplete, and search
Merge remote-tracking branch 'upstream/master'