Remove unused declaration (now moved to likely/function.h)
Implement Legendre polynomial evaluation for even ell up to 12.
Add free function to numerically evaluate an even multipole ell = 0-12 given f(mu).
* Implement Legendre polynomial evaluation for even ell up to 12.
* Add free function to numerically evaluate an even multipole ell = 0-12 given f(mu).