Fix a bug in SimpleSMTLIBSolver.Dispose() if the process hasn't started trying to call some methods will cause a InvalidOperationException to be thrown.
Fix a bug in SimpleSMTLIBSolver.Dispose() if the process hasn't started
trying to call some methods will cause a InvalidOperationException to be
thrown.

symbooglix/symbooglix,symbooglix/symbooglix,symbooglix/symbooglix