Adds SystemStateMachine classes and tests
renames SystemMethodProvider to DynamicSystemProvider
to match convention on EntityStateMachine
Merge changes for system state machine.
Simplify the interface for adding system providers to the engine state machine.
renames SystemStateMachineTests to EngineStateMachine
to match new class name
Merge pull request #24 from neilmanuell/EngineStateMachine

renames SystemStateMachineTests to EngineStateMachine
Build the .swc file.