Bug fix with adding elements with non-String ids

Added corresponding unit test
By default, set the create option for mock graphs
Make AccumuloGraphConfiguration extend AbstractConfiguration for simpler usage
Unit test updates

Initial commits for Mock/Distributed instance tests
New test for valid graph names
Update configuration validation
Separate out Features creation
setCreate by default for DistributedInstanceTest
Merge pull request #91 from JHUAPL/unit-test-updates

Unit test updates
Lots of updates to README.md
Let's use AccumuloGraphException instead of RuntimeException
Initial commit for table structure documentation
More README.md updates
Merge pull request #93 from JHUAPL/readme-update

Readme update
Update to SNAPSHOT version (for now)
Merge branch 'master' into table-wrappers
Rename configuration methods for more clarity
Pass around a "GlobalInstances" object to simplify passing globals relevant to multiple AccumuloGraph objects
Refactor VertexTableWrapper and EdgeTableWrapper operations to use element objects
Refactor property operations to use GlobalInstances object
Several changes

Refactoring of wrappers to use GlobalInstances object
Added VertexTableWrapper and EdgeTableWrapper to GlobalInstances
Started moving vertex.getEdges() to VertexTableWrapper