Parse get-model responses with valuation pairs

[Franck Cassez]

Z3/CVC4/MathSat use different types of S-Expression to return a model. For instance Z3 returns a (model fundef ...) S-expr while MathSat and CVC4 returns valuation pairs.

Add ability to parse the different types of getModelResponses.

[Franck Cassez]

Add ability to parse get-model as model/fundef (Z3 style) and valuation pairs (CVC4/MathSat style).

resolve #18

→ <<cset d77ab7ee2a67>>