tensor weights in eHandler after fixpoint computation in Newton.

This weights are used during path summary, and to read off weights of the
output automaton after poststar. We want to (possibly repeated) computation of
tensor later. So tensor them early.
BinRel::Tensor optimization: Under NWA_DETENSOR, don't reverse if second elem is id
Alternate pairing of weights in Newton to reduce the number of reverse operations

In this scheme of pairing, the transposed element is kept as the right element instead of the the left element as before.
This means that
(1) The weight obtained after path_summary is transposed from the actual weight.

For more details look at the updated comments in setupNewtonSolution
Update NewtonCompare to transpose weight before comparing.

There was also a possible bug -- at two places the weight obtained after
poststar under newton was being compared to zero without tensoring, this would
come out to be nonzero in many cases when the detensored weight is zero,
leading to false positive.
BddContext: Add numReverse to stats to track number of vocabulary reverse operations.
Separate out reverse from tensorViaDetensor for better profiling.
BddContext::Stats -- track the top level detensor[Tranpose] invocations.

because we have multiple implementations now. The counting was deeper down,
hence missed some implementations.
Added Examples/cprover/CheckRecursive. This programs decide if the given bpl is recursive.