eina: Refer to sin/cos as sine/cosine instead of sinus/cosinus

Summary:
Sinus and cosinus are just the Latin words for sine and cosine, but we
should use the English versions to avoid any possible confusion.

Reviewers: Hermet

Reviewed By: Hermet

Subscribers: cedric, reviewers, committers

Tags: efl

Differential Revision: https://phab.enlightenment.org/D7059