better exception msg
Merge branch 'indexing' of github.com:thinkaurelius/titan into indexing
Allow Titan Server to initialize scriptengine with a script.

Similar to functionality with Rexster.  Allows server-side logic to be initialized to the scriptengine for future calls through the script engine via RexPro.
Registered storage backends and index providers
BerkleyJE create data directory if it doesn't exist