Review and improve trigonometric functions

[ckormanyos]

Review and improve the trigonometric functions sin(), cos() and tan(). Include also asin(), acos() and atan()

• Check for efficient runtime performance.
• Verify small-angle approximations.
• Verify approximations for $32$, $64$ and $128$ bit implementations.
• Try for $100\%$ codecov if not already tested to that level.

Hi @ibmibmibm this one has been on my personal list for a while. But I never find time to do it.

Cc: @mborland