Added entities hierarchy to schema, multiple aspects for entity, entity
positioning and recording options.
Merge branch 'development' into replay

Conflicts:
	src/main/java/org/geppetto/simulation/SimulationService.java
Added visitor for simulation tree and unit tests. Work in progress.
Added instance path tree decorator and its unit test, a runnable to
create a service and a visitor to create a service for each model and
simulator node of the simulation tree. Work in progress.
Simulation refactoring
Moved simulation model from simulation to core bundle
Merge branch 'development' into replay

Conflicts:
	src/main/java/org/geppetto/simulation/SimulationService.java
Refactoring propagation
Merge remote-tracking branch 'origin/development' into replay

Conflicts:
	pom.xml
	src/main/java/org/geppetto/simulation/SimulationService.java
POM update
Added method to throw error. Replaced RuntimeException with error
handling which propagates to the frontend.
Merge remote-tracking branch 'origin/development' into replay

Conflicts:
	src/main/java/org/geppetto/simulation/SimulationService.java
Missed resource
Ongoing refactoring
Various fixes
Added simulator able to replay recordings
Merge pull request #55 from openworm/replay

Merging replay branch