TimeOfFlightHyperbola:

 Time of flight in a hyperbola
 This function gives the time of flight between two true anomalies.
 This function only works for hyperbolas. It will throw an error
 if either true anomaly is outside the maximum true anomaly for the 
 hyperboal.

 Type TimeOfFlightHyperbola for a demo in lunar orbit.

--------------------------------------------------------------------------
   Form:
   t = TimeOfFlightHyperbola(a,e,nu1,nu2,mu)
--------------------------------------------------------------------------

   ------
   Inputs
   ------
   a   (1,1)   Semi-major axis
   e  	(1,1)   Eccentricity
   nu1	(1,1)   True anomaly (rad)
   nu2	(1,1)   True anomaly (rad)
   mu  (1,1)   Gravitational parameter

   -------
   Outputs
   -------
   t   (1,1)   Time of flight

--------------------------------------------------------------------------
   Reference: http://www.braeunig.us/space/orbmech.htm equation 4.86
--------------------------------------------------------------------------