CSP engine mod
Fixes small DFS flag issue
Engine framework
Refactors CSPExecutor as an Engine
Engine, Frontier moved to dg-core; DefaultDistributor works with Frontiers
Retypes the dfs solution queue
SCXML engine
Adds Json functionality to Frontier
Removes old SCXML code
Moves new SCXML code to dg-core, corrects coding style
SCXMLEngine sets all variables to default value before bootstrap search
DataConsumer exit flag overhaul
Merge pull request #4 from mpeter28/master

Pull hadoop example changes
Merge branch 'csp' of https://github.com/mpeter28/DataGenerator into csp
Fixes examples
Small bug fixes
SCXMLFrontier logging
Remove CSP materials
Unit Tests for SCXML Engine and Frontier
SCXMLGapper unit tests