There is no explicit model type keyword added to the parser.
Instead, LTSs are auto-detected by the absence of probabilities.
ConstructModel is extended to build LTSs. Model checking (CTL+LTL)
can be done out of the box using the existing NonProbModelChecker class.
A few MDP regression tests are clarified to make it clear that the
models are MDPs, not LTSs.
Code is split into different methods for each type of test.
It is also mostly relocated to a new class prism.ResultTesting,
since it should not really be tied to the Property object.
The result for testing can now be passed as a Result object,
as well as Double, Integer, etc., with the former being preferred.
This will allow info attached to the Result object to be used
for the correctness, notably accuracy/error info.
Also add a new testing regression test - just some constants,
including border cases - infinity, NaN, etc.
Dave Parker