This completes the work started in !4 by implementing the true
Reynolds recalculation for the other three solvers.

Note that special care had to be implemented in Stahlhut solver in order
to ensure proper numerical resolution of the solution.

calculate reynolds number exact value in indvel.m
use its exact value when possible, if not use an approximation in ElemPerf.m

The root cutout is at 5ft, then the blade morphs towards a cylinder of
3ft radius. So the blade actually stops at 5ft and not 3.

As described in page 19, the non-dimensionalization uses a factor 1/2.
This factor is associated with the "European" convention, while it does
not appear in the US one (see Leishman, Principles of Helicopter
Aeroydnamics, Eq 2.36).