FLoating Point Issues in Takeuchi Starting Conditions

[jrenaud90]

An earlier version of TidalPy used the full definition of Takeuchi & Saito (1972)'s starting conditions in the radial function.
However, testing revealed that there were issues matching the limiting values (as z -> 0) since the full solution has terms that are like: (Very Big) / (Very Big) ~ near 1. Errors would compound leaving the final answer larger or smaller than 1.

Current Solution:
Have reverted back to using the limiting version of these equations.