[FEATURE REQUEST] Backward analysis (final version)

[lucaneg]

Description As an extension and finalization of #120, we should:

• swap the evaluation of sub-expressions with the outer-most one in NaryExpression and NaryStatement
• provide a proper backward interproceduralAnalysis
• provide a proper backward HeapDomain
• provide a proper backward TypeDomain
• investigate the need of a backward CallGraph
• Support optimiziations (classes are there but results are unstable)
• Thoroughly test the backward framework