* Separate data structures for BeliefMDPState and POMDPStrategyModel
* Push reward construction/storage into the code for the belief MDP
* Factor out prob/reward backup operations into methods for re-use
* Store value function + backup using functional interfaces
* Collapse (now simpler) buildStrategyModel into one method
This is a rebased version of the code previously published in the prism-ext repo,
with various bits of code refactored, tidied and improved.
Model construction and model checking support is added to the explicit engine.
The PRISM modelling language is extended with the 'pomdp' model keyword
and observables...endobservables blocks to indicate observable variables.
Dave Parker