- Adds capturing config, numTotalVertices, numTotalEdges, and aggregators: currently an aggregator is captured only if it is read by some vertex. Also we do not yet do anything for adding new aggregators.
- Adds the necessary proto files for aggregators and their wrapper classes, AggregatorWrapper.java and  AggregatedValueWrapper.java.
- Refactors the wrapper classes to accomodate for the aggregator wrapper classes.
- Fixes the exmaples for msg integrity and value integrity.
- Adding AggregatedValueWrapper.java.