Implement the graphbuilder:

process the file and build the Rule

Summary: build the graph from the JSon Object Tree

Test Plan: Review, execute the main (uncomment the src/graphbuilder.cpp print line)

Reviewers: adrien

Subscribers: NicolasDP

Differential Revision: http://91.121.199.76/D6
Merge branch 'master' of github.com:adrienconrath/Falcon