Support adding the old value of a modified vertex/edge property as a
part of the property modification event data.
Merge remote-tracking branch 'asaf/oldValueInEvent'
Minor code format changes on eventgraph.
Updated changelog
Added parameters argument to createKeyIndex.

Allow individual graph implementations to take advantage of additional parameters for configuring indices.
Changed EventTrigger class visibility to public,

This is required when extending EventGraph is neccessary as
EventTrigger instance is required as apart of the EventGraph constructor.
Merge pull request #346 from asaf/eventTriggerPublic

Changed EventTrigger class visibility to public,
hashCode implementation for Parameter class.

An existing implementation of Parameter.equals exist without
having an implementation of hashCode(), this violate the requirement
that equal must have an equal hashcodes.
Factored out VertexIDType (was enum in BatchGraph). Refactored caches to no longer require a graph object. Fixes #342.
Add FileInputStream helper functions to GraphMLReader
Add FileOutputStream helper functions to GraphMLWriter
GraphMLReader did not properly type cast properties.

Change the key type map so that it used the id per the graphml spec.
Add FileInputStream helper functions to GMLReader
Add FileOutputStream helper functions to GMLWriter
Add FileInputStream helper functions to GraphSONReader
Add FileOutputStream helper functions to GraphSONWriter
Upgraded to jackson 2 and fasterxml namespace. #350
Updated changelog.
Remove the final keyword from GraphSONUtility.

When parsing GraphSON stream, it may be required to extends
the functionality of the GraphSONUtility class and provide more specific implementation
for special cases.
Merge pull request #351 from asaf/exposegraphsonutility

Remove the final keyword from GraphSONUtility.