Merge pull request #202 from AdrienChampion/develop

Bug fix: two-state invgen would not guard with init for top level.
Broken commit before multi solver in lsd.
Modified state var handling in trans sys.
Cleaned a dirty thing in trans sys.
Fix in PDR.
Merge pull request #203 from AdrienChampion/fix_svar-declaration

Fixed svar unrolling, invGen uses 3 solvers now.