Convert NACA 4-digit airfoil to take floating point parameters.
Make 4-digit airfoil test plots in 2D
Change piecewise_four_digit_creator default constructor to only pass t0 to base constructor
Add four_digit airfoil pseudo curve member variable to piecewise_four_digit_creator
Set up piecewise_four_digit_creator to fit airfoil.
Update piecewise_four_digit_creator_test to actually fit airfoil
Comments about C1 and C2 fits for piecewise four-series airfoil.
Refactor bezier::fit to make minimum_distance based error calc optional.

The optimization based minimum_distance calculation performed at the end
of bezier::fit is quite expensive.  Although it is an important diagnostic,
it may not need to be calculated inside a fast loop of a production
program.

This refactoring makes the case where returned 't' values and the error
estimate are not required significantly faster.
Add four_digit creator to piecewise_creator includes
Comment out string toupper routine.

toupper can be implemented as a macro -- causing this to not work.  Various
fixes are possible, but I'm not sure which is the best choice.

As this is not very important, I'm just commenting it out.
Merge commit 'a542155ed583a03e9f380b6b20c5521572bd99de' into feature/NACA_4Series_Creator

* commit 'a542155ed583a03e9f380b6b20c5521572bd99de':
  Comment out string toupper routine.
  Add four_digit creator to piecewise_creator includes
  Refactor bezier::fit to make minimum_distance based error calc optional.
  Comments about C1 and C2 fits for piecewise four-series airfoil.
  Update piecewise_four_digit_creator_test to actually fit airfoil
  Set up piecewise_four_digit_creator to fit airfoil.
  Add four_digit airfoil pseudo curve member variable to piecewise_four_digit_creator
  Change piecewise_four_digit_creator default constructor to only pass t0 to base constructor
  Make 4-digit airfoil test plots in 2D
  Convert NACA 4-digit airfoil to take floating point parameters.
Changed string comparison for NACA airfoils to succeed on "NACA", "naca", or "Naca"
Fixed release build warning of unused variable, err. It was only used in the assert which doesn't get used in release builds. If error occurs, then should return false anyways.
Merge branch 'feature/NACA_4Series_Creator' into develop