Refactoring code and removing timeout during test

...main/scala/leon/invariant/datastructure/DisjointSet.scala

src/main/scala/leon/invariant/datastructure/Graph.scala

src/main/scala/leon/invariant/datastructure/Maps.scala

...a/leon/invariant/engine/CompositionalTemplateSolver.scala

...in/scala/leon/invariant/engine/InferInvariantsPhase.scala

src/main/scala/leon/invariant/engine/InferenceContext.scala

src/main/scala/leon/invariant/engine/InferenceEngine.scala

src/main/scala/leon/invariant/engine/InferenceReport.scala

src/main/scala/leon/invariant/engine/RefinementEngine.scala

src/main/scala/leon/invariant/engine/SpecInstatiator.scala

...main/scala/leon/invariant/engine/TemplateEnumerator.scala

...scala/leon/invariant/engine/UnfoldingTemplateSolver.scala

src/main/scala/leon/invariant/factories/AxiomFactory.scala

...main/scala/leon/invariant/factories/TemplateFactory.scala

...scala/leon/invariant/factories/TemplateInstantiator.scala

src/main/scala/leon/invariant/structure/Constraint.scala

src/main/scala/leon/invariant/structure/Formula.scala

src/main/scala/leon/invariant/structure/FunctionUtils.scala

...scala/leon/invariant/structure/LinearConstraintUtil.scala

...in/scala/leon/invariant/templateSolvers/CegisSolver.scala